WO2024105679A1 - Dental kit and method for performing maxillary sinus lift procedure using a crestal approach - Google Patents

Abstract

The invention relates to devices and methods of sinus lifting, the method comprising selecting a patient with a potential implant location in an upper jaw adjacent a sinus and having a crestal height of 4 mm or less at said location; forming a crestal access path to said sinus; lifting said a sinus membrane of said sinus via said access path; and implanting a support in said sinus under said sinus membrane.

Description

DENTAL KIT AND METHOD FOR PERFORMING MAXILLARY SINUS LIFT

PROCEDURE USING A CRESTAL APPROACH

RELATED APPLICATION/S

This application claims the benefit of priority of U.S. Provisional Patent Application No. 63/426, 763filed on 20 November 2022, the contents of which are incorporated herein by reference in their entirety.

FIELD AND BACKGROUND

The present invention, in some embodiments thereof, relates to a kit and method of sinus lifting and, more particularly, but not exclusively, to a kit utilizing bone burs with stoppers and sinus lifting via a crestal approach.

Additional background art includes scientific publication "Alveolar Crestal Approach for Maxillary Sinus Membrane Elevation with. " By Jang, Jae Won, et al. disclosing that “For maxillary sinus membrane elevation (MSME), the lateral window approach and crestal approach are available, and high success rates have been achieved with low residual bone height as a development of technology. The objective of the research was to evaluate MSME using the crestal approach with a rotary-grind bur (RGB (including reamer or sinus bur)) in patients with residual bone height of <4 mm. In the research, ten implants were placed in 10 patients with residual bone height of <4 mm, by sinus elevation using an RGB. The implant stability quotient (ISQ) was measured immediately after implant placement (ISQ 1) and before taking impression for the final prosthesis (ISQ 2). The extent of marginal bone loss was measured on periapical radiographs. Results. The mean residual bone height before implant placement was 3.41 ± 0.53 mm; no complications, including membrane perforation, severe postoperative pain, or discomfort, occurred either during or after surgery. The mean ISQ 1 was 63.4 ± 12.1, whereas the mean ISQ 2 was 77.6 ± 5.8. The mean marginal bone resorption was 0.23 ± 0.18 mm on periapical radiographs. It was concluded that MSME using the crestal approach with an RGB is a reliable technique for implant placement in sites where available bone is insufficient.”

Scientific publication “ Reamer -mediated transalveolar sinus floor elevation without osteotome and simultaneous implant placement in the maxillary molar area: clinical outcomes of 391 implants in 380 patients." by Ahn, Sang-Hoon, E”un-Jin Park, and Eun-Suk Kim, disclosing that “Minimally invasive sinus elevation and augmentation using a transalveolar approach can reduce perioperative complications and patient discomfort. A specially designed reamer accomplishes this without the use of an osteotome or a mallet. The objective of this study was to present this technique with relevant clinical cases and patient outcomes.”

Scientific publication “Use of a Biphasic Calcium Sulphate Graft to Treat Posterior Maxillary Atrophies by Avoiding a Lateral Sinus Approach” by Baranes, David, and Gregori M. Kurtzman, is after the priority date of this application and is not admitted as prior art, disclosing that “Augmentation of the maxillary sinus when severe atrophy and/or pneumatization of the sinus has occurred results in minimal crestal height that will not allow simultaneous implant placement has been a clinical challenge. The lateral sinus augmentation approach has been traditionally utilized in these clinical situations, but there are known complications such as membrane tears and increased post-operative issues that follow use of this technique. This article aims to propose a new technique utilizing specific surgical instruments, making it possible to increase the height of the crestal bone under the maxillary sinus in cases of significant atrophy, without complications using a two-stage crestal approach with a bi-phasic calcium sulphate as the graft material. The article will discuss the technique, present a case example and review 51 cases representing initially 1-3 mm sub sinus crestal bone heights that the technique was utilized with.” (abstract)

SUMMARY

Following is a non-exclusive list including some examples of embodiments of the invention. The invention also includes embodiments which include fewer than all the features in an example and embodiments using features from multiple examples, also if not expressly listed below.

Example 1. A method of sinus lifting, comprising:

(a) selecting a patient with a potential implant location in an upper jaw adjacent a sinus and having a crestal height of 4 mm or less at said location;

(b) forming a crestal access path to said sinus;

(c) lifting a sinus membrane of said sinus via said access path; and

(d) implanting a support in said sinus under said sinus membrane.

Example 2. The method according to example 1, wherein said method does not include forming a lateral access path to said sinus.

Example 3. The method according to any of the preceding examples, wherein said forming a crestal path comprises forming by drilling in stages, each stage using a bone removal device with a stopper, the stoppers defining increasing stopping distances.

Example 4. The method according to example 3, wherein said bone removal device is a one or more of a bur, a piezo surgery with active part and a hand tool with an active part. Example 5. The method according to example 3, wherein said drilling comprises using said bone removal device with an adjustable distance stopper.

Example 6. The method according to example 3, wherein said drilling comprises using a set of bone removal devices, each with a different fixed distance stopper.

Example 7. The method according to any of examples 3-6, wherein said increasing stopping distances are separated by less than a distance increase which would cause tearing of a sinus membrane at that distance increase from the inside of the sinus.

Example 8. The method according to example 7, wherein said distance increase is about 1 mm.

Example 9. The method according to any of examples 3-8, wherein said a first stage of said drilling uses a stopper set at 1 mm or less drilling depth.

Example 10. The method according to any of examples 3-9, wherein said first stage of said drilling comprises stabilizing said bone removal device on a surface of said crestal bone using a point at the center of a front surface of said bone removal device.

Example 11. The method according to any of the preceding examples, comprising implanting an implant in said implant location.

Example 12. The method according to any of examples 1-11, comprising waiting at least 3 weeks for healing and repeating said (c)-(d) and thereafter implanting an implant in said implant location.

Example 13. The method according to example 11, repeating said (b), when repeating said (c)-(d).

Example 14. The method according to any of the preceding examples, wherein said forming comprises detecting when the path reaches the sinus by tactile feel of an abrupt change in crestal resistance.

Example 15. The method according to any of the preceding examples, wherein said forming comprises drilling said crestal path all the way to the sinus membrane.

Example 16. The method according to any of the preceding examples, wherein said forming comprises drilling using a non-sharp bone removal device.

Example 17. The method according to example 16, wherein said non-sharp bone removal device has a flat front surface extending at least 70% of a cross-sectional area of said bone removal device detecting, measured in a transverse plane to the crestal direction which is an axial direction of the bone removal device.

Example 18. The method according to example 17, wherein said non-sharp bone removal device has a shape of a truncated cone. Example 19. The method according to example 16, wherein said non-sharp bone removal device has a concave front surface extending at least 70% of a cross-sectional area of said nonsharp bone removal device, measured in a transverse plane to the crestal direction which is an axial direction of the non-sharp bone removal device.

Example 20. The method according to any of examples 16-19, wherein a forward facing rim of said non-sharp bone removal device has a rounded edge facing forward.

Example 21. The method according to any of examples 16-20, wherein said forming a crestal access path comprises penetrating the crestal bone with a non-sharp bone removal device having a concave front surface.

Example 22. The method according to example 21, wherein said penetrating the crestal bone comprises terminating said forming of said crestal access path when a separated portion of said crestal bone is formed.

Example 23. The method according to example 22, comprises confirming penetration into said crestal bone by viewing said sinus membrane around said separated portion of said crestal bone

Example 24. The method according to any of the preceding examples, wherein said support comprises a flowable bone or bone-inducing growth or bone scaffold material.

Example 25. The method according to example 11, wherein said implanting a support comprises implanting in stages.

Example 26. The method according to example 11 or example 25, wherein said implanting a support comprises filling said crestal access path with said support.

Example 27. The method according to any of examples 11 or examples 25-26, wherein said filling said crestal access path comprises using a bone filler injector with a front end having an outer diameter larger than the diameter of the crestal access path, wherein said front end contacts an opening of said crestal access path during said filling.

Example 28. The method according to any of examples 1-26, wherein said lifting comprises lifting in stages using a tool with a stopper which stopper sets a raising distance for the stage.

Example 29. The method according to any of examples 1-26, wherein said lifting comprises lifting in stages of 0.8- 1.2 mm.

Example 30. The method according to example 28, wherein said tool comprises an osteotome.

Example 31. The method according to example 23, wherein said lifting comprises pushing said separated portion of said crestal bone using an osteotome having a flat distal surface with a gentle dome at the center thereof, wherein said dome axially protrudes from said distal surface by no more than 0.35 mm, and wherein a surface of said dome occupies no less than 50% of said distal surface.

Example 32. The method according to any of examples 28-30, wherein said tool is part of a set of tools with fixed stoppers at different distances.

Example 33. The method according to example 1, comprises exposing the crestal bone by a single flap prior to said forming a crestal bone.

Example 34. The method according to example 33, wherein said exposing the crestal bone comprises creating a single incision near the center of the crestal bone, at a portion located close to the palate.

Example 35. The method according to example 34, wherein said creating a single incision, does not include creating a second incision near the gingiva.

Example 36. A method of sinus lifting, comprising:

(a) selecting a patient with a potential implant location in a jaw;

(b) forming a crestal access path, using at least one bone removal device with a flat or concave distal surface;

Example 37. The method according to example 36 wherein said forming a crestal access path comprises forming a crestal access point using at least one bone removal device with a concave sinus membrane.

Example 38. The method according to example 36 wherein said forming a crestal access path comprises forming a crestal access path in stages of increasing penatrtion depth.

Example 39. The method according to example 36-38, wherein said selecting comprises selecting a patient with a potential implant location in an upper jaw adjacent to a sinus.

Example 40. The method according to any of examples example 36-39, wherein said method does not include forming a lateral access path to said sinus.

Example 41. The method according to any of examples example 36-40, wherein said forming a crestal access path comprises forming a crestal access path to said sinus.

Example 42. The method according to any of examples 36-41, comprises lifting said a sinus membrane of said sinus via said access path.

Example 43. The method according to any of examples 36-42 implanting a support in said sinus under said sinus membrane.

Example 44. The method according to any of examples 36-43, wherein said selecting comprises selecting a patient with a potential implant location in an upper jaw adjacent a sinus and having a crestal height of at least 4 mm at said location. Example 45. A dental bur for sinus lifting, comprising: an elongate shaft with a proximal end configured for attaching to a dental drill bit- socket; a dental bone bur head with a diameter of 4 mm or less and a front surface; and a stopper with a stopping surface positioned 1 mm or less from said front surface of said bur head, wherein said front surface defines a drilling diameter of at least 2 mm and an axial extent of less than 0.5 mm.

Example 46. The dental bur according to example 45, wherein said head is shaped as a cylinder.

Example 47. The dental bur according to any of examples 45-46, wherein said head has a diameter of 2.8-4 mm.

Example 48. The dental bur according to example 45, wherein said front surface comprises a non-sharp of a non-pointy surface.

Example 49. The dental bur according to example 48, wherein said non-sharp bur has a shape of a truncated cone.

Example 50. The dental bur according to example 48, wherein said front surface is flat.

Example 51. The dental bur according to example 48, wherein said non-sharp dental bur has a flat front surface extending at least 70% of a cross-sectional area of said dental bur, measured in a transverse plane to the crestal direction which is an axial direction of the dental bur.

Example 52. The dental bur according to example 48, wherein said front surface is concave.

Example 53. The dental bur according to example 48, wherein said non-sharp bur has a concave front surface extending at least 70% of a cross-sectional area of said bur detecting, measured in a transverse plane to the crestal direction which is an axial direction of the bur.

Example 54. The dental bur according to any of examples 45-53, wherein a forward facing rim of said bur has a rounded edge facing forward.

Example 55. The dental bur according to any of examples 45-54, wherein said front surface drilling diameter is at least 60% of a maximal diameter of said head.

Example 56. The dental bur according to example 48 wherein said front surface is non- pointy except for a point at the center thereof, wherein said head defines an axis of rotation and wherein said point is located along said axis of rotation.

Example 57. The dental bur according to example 56, wherein the point occupies no more than 10% of the front surface. Example 58. The dental bur according to any of examples 56-57, wherein said point protrudes axially no more than 0.5 mm, from said flat front surface or from said forward facing rim of said concave front surface.

Example 59. The dental bur according to any of examples 45-55, wherein said stopper is integral and fixed in location relative to said elongate shaft and said head.

Example 60. The dental bur according to any of examples 45-59, wherein said stopper is movable relative to said front surface.

Example 61. The dental bur comprising a bur according to any of examples 45-60, in combination with additional burs with different stopping distances, in steps of less than 1.1 mm.

Example 62. A dental bur kit for sinus lifting comprising: a plurality of bone burs with a drilling diameter of less than 4 mm, each bur comprising: a head having a front bone removal surface; and a stopper having a stopping surface distanced a stopping distance from said head, wherein each bur has a different stopping distance, the starting distances starting from 1.1 mm or less and increasing in steps of less than 1.1 mm until at least 4 mm.

Example 63. The kit according to example 62, wherein said front bone removal surface is flat or concave over at least 60% of its area.

Example 64. The kit according to example 63, wherein said plurality of bone burs comprises at least one dental bur, wherein the front bone removal surface thereof comprises a point at the rotation center, configured to be used at a first stage of forming a crestal access path.

Example 65. The kit according to any of examples 63 or 64, wherein said plurality of bone burs comprises at least one dental bur comprising a concave front bone removal surface and configured to be used at a last stage of forming a crestal access path.

Example 66. The kit according to example 62 or example 63, comprising an additional plurality of bone burs with a stopping distance of above 5 mm.

Example 67. The kit according to example 66, wherein a drilling diameter of said additional plurality of bone burs is different from a drilling diameter of said plurality of bone burs.

Example 68. The kit according to any of examples 62-67, comprising a plurality of osteotomes, each having a stopper, each stopper set at a different stopping distance and at least one suitable for reaching 5 mm or less.

Example 69. The kit according to any of examples 62-68, comprises an adjustable osteotome, having a movable stopper along the longitudinal length thereof, wherein moving the stopper modified a length of an active part of the osteotome. Example 70. The kit according to example 69, wherein the adjustable osteotome comprises markings for indicating the length of the active part.

Example 71. The kit according to any of examples 68-70 wherein the osteotome comprises a flat distal contact surface with a gentle dome at a center thereof, wherein said dome axially protrudes from said distal surface by no more than 0.35 mm, and wherein a surface of said dome occupies no less than 50% of said distal surface.

Example 72. The kit according to example 71, wherein said contact surface of said osteotome comprises a smooth rim.

Example 73. The kit according to any of examples 62-68, comprising a bone filler injector and bone filler material.

Example 74. The kit according to example 73, wherein an outer diameter of said bone filler injector, is larger than an opening of said crestal access path.

Example 75. A dental bur kit for sinus lifting comprising: a plurality of bone burs wherein, each dental bur comprises: a head having a front bone removal surface; and a stopper having a stopping surface distanced a stopping distance from said head, wherein each bur has a different stopping distance, the starting distances starting from 4.1 mm or less and increasing in steps of less than 1.1 mm until at least 10 mm.

Example 76. The kit according to example 75, wherein each bone bur of said plurality of bone burs has a drilling diameter of less than 5 mm.

Example 77. The kit according to any of examples 75-76, wherein said front bone removal surface is flat or concave over at least 60% of its area.

Example 78. The kit according to any of examples 75-77, wherein said kit comprises an adjustable osteotome, having a movable stopper along the longitudinal length thereof, wherein moving the stopper modified a length of an active part of the osteotome.

Example 79. The kit according any of examples 75-78, wherein the adjustable osteotome comprises marking for adjusting the length of the active part.

Example 80. The kit according to any of examples 75-79, wherein the osteotome comprises a flat distal contact surface with a gentle dome at a center thereof.

Example 81. The kit according to example 80, wherein said contact surface of said osteotome comprises a smooth rim.

Example 82. The kit according to example 75, comprises a bone filler injector and bone filler material. Example 83. The kit according to example 83, wherein the bone filler injector is larger than the opening of the crestal access path.

Example 84. The kit according to any of examples 82-83, wherein the bone filler injector is a bone filler syringe with an opening of about 4.5 mm.

Example 85. A method of forming a crestal path for sinus lifting, comprising: exposing a jaw bone; and drilling into said jaw bone until reaching into a sinus, while avoiding damaging sinus membrane in said sinus, wherein said avoiding comprises one or both of using a non-sharp bone bur and using a stopper of less than 1.2 mm to limit bur penetration.

Example 86. An osteotome, for lifting a sinus membrane during maxillary sinus lift procedure, comprising: an elongated body; a cylindrical active part mounted on said elongated body at one end thereof; and a contact surface at a second end there, wherein the contact surface comprises a flattened dome, having a height of no more than 0.35 relative to said contact surface and occupies no less than 50% from said contact surface.

Example 87. The osteotome of example 86, wherein said contact surface comprises a smooth rim.

Example 88. The osteotome of any of examples 86-87, wherein said elongated body comprises a stopper, and wherein said active part is mounted on said body.

Example 89. The osteotome of any of examples 86-88, wherein said osteotome is an adjustable osteotome, having a movable stopper along the longitudinal length thereof, wherein moving the stopper modified a length of the active part of the osteotome.

Example 90. The osteotome of any of examples 86-89, wherein the adjustable osteotome comprises markings for indicating the length of the active part, wherein intervals between the markings are 1 mm.

Example 91. A method for confirming crestal bone penetration in maxillary sinus lift of crestal bone of at least 4 mm, comprising;

(a) forming a crestal access path to said sinus, using at least one dental bur;

(b) inserting an osteotome having an active part longer than a head of said dental bur path;

(c) assessing if a stopper of said osteotome is obstructed by the crestal bone or if said active part is completely inserted into said access path; (d) proceeding forming said access path using a dental bur with a head of the same length as the osteotome

(e) alternating between accessing and proceeding using dental bur’s heads and osteotome in ascending order until the osteotome active part fully inserted into said access path.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings and images. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.

In the drawings:

FIG. 1 is a flow chart of a general method for a maxillary sinus lifting procedure, performed using a crestal approach, in accordance with some exemplary embodiments of the invention;

FIGs. 2A-B are general schematic side views of two dental burs, in accordance with some exemplary embodiments of the invention;

FIGs. 2C-D show a schematic illustration showing the formation of an access path to the sinus cavity through the crestal bone, and the interaction of a flat distal surface of a dental bur with the sinus membrane, in accordance with some embodiments of the invention;

FIGs. 2E-J are a schematic illustration of a dental bur with an adjustable stopping distance, in accordance with some embodiments of the invention;

FIGs. 2K-P are a general schematic side views of various embodiments of a dental bone bur, in accordance with some embodiments of the invention;

FIG. 3A is top angled perspective view of dental bur shaped as cylinder with a flat distal surface, in accordance with some exemplary embodiments of the invention; FIG. 3B is top angled perspective -view of dental bur shaped as cylinder with concave distal surface, in accordance with some exemplary embodiments of the invention;

FIG. 4A is an illustration of a dental kit, comprising a set of dental burs, osteotomes, a bone carrier syringe and a dish for placing a bone carrier syringe, in accordance with some embodiments of the invention;

FIG. 4B is an example of a set of dental burs, consist of dental burs with heads of flat distal surface of different lengths and uniform head shape, in accordance with some exemplary embodiments of the invention;

FIG. 4C is an example of an osteotome with an adjustable stopper, in accordance with some embodiments of the invention;

FIGs. 5A-C are a flow chart describing a method for a maxillary sinus lifting procedure, performed using a crestal approach, in accordance with some exemplary embodiments of the invention;

FIGs. 6A-J illustrate stages of an osteotomy procedure, in accordance with some exemplary embodiments of the invention;

FIGs. 7A-I show, schematically, stages in performing a maxillary sinus floor elevation, via a crestal approach, in accordance with some embodiments of the invention;

FIGs. 8A-8C are images of some stages in an osteotomy procedure, in accordance with some embodiments of the invention;

FIG. 9A is a schematic side view of a dental bur, having a point extending from a distal surface thereof, in accordance with some embodiments of the invention;

FIG. 9B is a perspective top view of a head with a point, in accordance with some of the embodiments of the invention;

FIG. 10A is a schematic side view of an embodiment of a dental bur, in accordance with some of the embodiments of the invention;

FIG. 10B is a schematic side view of an embodiment of a dental bur’s head, in accordance with some of the embodiments of the invention;

FIG. IOC is a cross-section of an embodiment of a dental bur’ s proximal end, in accordance with some of the embodiments of the invention;

FIG. 11 A is a side view of a dental kit, comprising at least one dental bur with a point and at least one dental bur with a concave distal surface, in accordance with some of the embodiments of the invention; FIG. 1 IB is a top view of a dental kit, comprising at least one dental bur with a point, and at least one dental bur with a concave distal bone removal surface, in accordance with some of the embodiments of the invention;

FIGs. 12A-B show schematically steps of a maxillary sinus floor elevation using a kit comprising at least one dental bur with a point, and at least one dental bur with a concave distal surface, in accordance with some of the embodiments of the invention;

FIG. 13 shows a sinus elevation procedure using an osteotome with a gently domed flat contact surface, in accordance with exemplary embodiments of the invention;

FIGs. 14A-C shows sinus elevation through an access path with a separated bone portion using an osteotome with a gently domed flat contact surface, in accordance with exemplary embodiments of the invention;

FIGs. 15A-B is an osteotome with an adjustable stopper, in accordance with exemplary embodiments of the invention;

FIG 15C is an osteotome with an adjustable stopper obstructing further penetration into an access path, in accordance with exemplary embodiments of the invention;

FIGs. 16A-E shows schematically stages in performing gradual filing of an access path with a bone graft, in accordance with exemplary embodiments of the invention;

FIGs. 17A-D is an example of a gradual filing of the access path with a bone graft, in accordance with exemplary embodiments of the invention.

FIGs. 18A-B shows exemplary components of a dental kit for performing sinus membrane elevation of a crestal bone with an initial bone height of at least 4 mm and/or for performing the second stage of a two-stage sinus elevation procedure, in accordance with exemplary embodiments of the invention;

FIG. 19 is an example of a full-thickness flap at the extraction socket, in accordance with exemplary embodiments of the invention;

FIG.s 20A-D shows an example of the second stage of a two-stage procedure, in accordance with exemplary embodiments of the invention; and

FIG.s 21A-T shows an expmle of two-stages sinus lift procedure, in accordance with exemplary embodiments of the invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to a kit and method of sinus lifting and, more particularly, but not exclusively, to a kit utilizing bone burs with stoppers and sinus lifting via a crestal approach.

RECTIFIED SHEET (RULE 91) An aspect of some embodiments of the inventions relates to a dental bur for dental crestal drilling, for forming a crestal access path to the sinus with reduced risk of sinus membrane perforation. The access path can be formed by kinds of osteotomy methods, such as drilling, grinding and/or milling. In some embodiments, a dental bur with an active part covered with diamond grains is used for grinding the bone. In some embodiments of the invention, the bur has a non-pointy tip at a distal side of a head thereof, which may prevent damage to a sinus membrane and/or a stopper which prevents over-insertion of the tip. In some embodiments, a non-pointy tip refers to a surface that does not significantly protrude from a plane perpendicular to the drilling direction. Optionally, in some embodiments, a set of burs is provided, each one with a different stopping distance, so that one may start with a short distance and increase the distance if penetration to the membrane is not yet achieved, while still allowing to avoid over penetration to the membrane, which might damage the membrane. In some embodiments of the invention, the tip of the dental bur is in the form of a flat or concave surface. In some embodiments of the invention, when used, a proximal end of the dental bur is connected to a dental drilling device. In some embodiments, the non- sharp and/or non-pointy surface of the head of the dental bur is first to interact with the crestal bone. In some embodiments, when crestal bone is penetrated into the sinus, the flat distal surface the dental bur is generally tangent to the sinus membrane and potentially is less likely to damage the sinus membrane. Optionally or additionally, the lack of a sharp and/or pointy tip reduces risk of such penetration. Optionally or additionally, the use of a stopper prevents over extension of the tip into the sinus. A potential advantage of this design is that the drilling can proceed all the way into the sinus, using the dental bur, rather than using an osteotome to finish the last step of penetration.

In some embodiments of the invention the head of the dental bur has the shape of a cylinder or of a truncated cone with flat upper surface.

In some embodiments, optionally, the distal non-sharp and/or non-pointy surface has an area of at least 50%, 70%, 80%, 90% or intermediate or greater percentages of a cross-sectional area of the head. Optionally or additionally, forward facing edges on the distal surface are rounded to reduce risk of damage to the sinus membrane.

In some embodiments of the invention, the front surface is concave. In some embodiments, the head is cylindrical.

In some embodiments of the invention, the stopper has a fixed location relative to the distal surface. In some embodiments, the length of a shaft on which the stopper and head are mounted is, for example, between about 28mm and about 45mm. Optionally between about 18mm and about 55 mm, optionally between about 8mm and about 65 mm. In some embodiments of the invention, the stopper is disc shaped and extends radially between about 0.5mm and about 4mm, optionally between about 0.3mm and about 5mm, optionally between about 0.1mm and about 7mm, past a maximum radial extent of said head.

An aspect of some embodiments of the invention relates to a dental bur with a fixator element, for example a spike (also termed “point” in this disclosure), located at a center of rotation of the contact surface (e.g., distal surface). This fixator can be used to pin the bur to a bone surface and potentially reducing lateral slippage of the dentalbur . In some embodiments, the fixator is axially pushed into the crestal bone in the designated drilling site to potentially reduce the risk of deviation of the drilling which can lead to misplacement of the drilling site. In some embodiments, the drilling is performed after a previous step of sinus lifting (when performing a second stage of a two-stage procedure), and the fixator is used for placing the dental bur at the location of a closed previous path.

In some embodiments, while the fixator is pointy, the front surface of the dental bur as a whole, is non-pointy. For example, the fixator can be a protrusion on a flat and/or concave surface, optionally, positioned at the center thereof. In some embodiments, the contact surface is the portion of the dental bur which contacts the crestal bone. In some embodiments, the fixator is relatively small relative to the contact surface thereof so that the attributes of the distal non-pointy surface are not and/or less impaired. In some embodiments, the fixator allows the non-sharp and/or non- pointy surface to be stabilized relative to the surface of the bone at the beginning of the drill while still allowing substantially uniform grinding of the bone. In some embodiments, the fixator has a relatively limited length extending away from the surface (for example, no more than 1 mm), such that if the bone is penetrated using the dental bur with the fixator, there is no added risk to the sinus membrane.

An aspect of some embodiments of the invention relates to a dental kit, for use in a maxillary sinus floor elevation procedure, for drilling a vertical sub-sinus osteotomy of the residual crestal bone through the extraction socket, where the kit includes a plurality of bone burs with stoppers, each defining a stopping distance. In some embodiments of the invention, the stopping distances are selected to start at short distances, such as less than 1.1mm (for example 1mm, 0.8mm, 0.7mm, 0.5mm.) and to increase by small steps, for example, less than 1.1mm (for example 1mm, 0.8mm, 0.7mm, 0.5mm). In some embodiments, the stopping distances are selected to start at short distances of from about 1.1mm to about 0.1mm, optionally from about 1mm to about 0.3mm. Optionally from about 0.7mm to about 0.5mm. In some embodiments, the increase by small steps is of a distance of from about 1.1mm to about 0.1mm, optionally from about 1mm to about 0.3mm. Optionally from about 0.7mm to about 0.5mm. A potential advantage of this selection is that the risk of damaging a sinus membrane is reduced, as the advance is desirably less than an amount which may tear the membrane. In some embodiments of the invention, the kit also includes one or more osteotomes. “Osteotome” is referred to a tool with dimensions suitable to enter the drilled access path and reaching the sinus membrane. In some embodiments, the osteotomes are used, for example, to separate between the membrane of the sinus and the bone. In some embodiments, the osteotomes also comprise a fixed stopper configured to control the depth to which the osteotome is inserted. In some embodiments, a potential advantage of having a stopper in the osteotome is that is potentially reduces the possibility of damaging the sinus membrane. Optionally, a bone carrier syringe and dish for placement of bone graft, is provided as well.

In some embodiments of the invention, instead of a set of osteotomes and/or dental burs, each with a fixed stopper defining a stopping distance of a tip of the osteotome and/or the dental bur (e.g., with the stopper wider than the diameter of the osteotome head or the bur head), adjustable osteotomes and/or dental burs are provided, in which the stopper can be moved relative to the distal end of the osteotome or the dental bur. Optionally, the stopper (or set of osteotomes and/or dental burs) includes a range of distances, for example, from between 1mm and, for example, between 5mm and 15mm. For example, a range of distances of from about 0.5mm to about 20mm, optionally from about 0.1mm to about 25mm.

In some of the embodiments of the invention the adjustable osteotomes and/or the fixed set of osteotomes is used for gradually lifting of the sinus membrane and for gradually pushing bone graft into the sinus cavity. Optionally or alternatively, the set of dental burs and/or a dental bur with an adjustable stopper, used for drilling the access path, can be used for lifting the sinus membrane and for pushing a bone graft to the sinus cavity through the access path, instead of the osteotomes.

In some of the embodiments of the invention the dental kit is divided to a first set and a second set of burs, with different stopping distances, diameters and/or shapes. In one example, the first set comprises burs with stopping distances of from about 1mm to about 5mm and a diameter that is optionally between about 3.5mm and about 5mm, and the second set of burs has stopping distances of between about 6mm and about 10mm, with a smaller diameter, for example, form about 3mm to about 3.5mm. In some embodiments, the first set may have flattened heads, while the second set may use more conventional rounded or pointed heads. In cases when the bony crest level is less than 4mm the clinician may use the first set and optionally, following that, the second set. In cases when the bony crest level is above 4mm, the clinician may use only the second part of the kit. An aspect of some embodiments of the invention relates to performing a stepped sinus lift procedure using a crestal approach, which allows the practitioner to control the procedure which potentially reduces the risk of sinus membrane perforation. In some embodiments, the procedure includes stepped formation of a path to the sinus membrane, optionally using non-pointy dental bur(s). In some embodiments, the stepped formation is performed by using dental bur(s) with limited penetration depth, in ascending order of length. This has the potential advantage of preventing uncontrolled direct drilling and allows the practitioner to oversee the production of the griding. Additionally, the steeped progression reduces undesired enlargement of the access path. In some embodiments, the limited penetration depths of the dental burs are fixed. Alternatively or additionally, the penetration depth is adjustable.

In some embodiments, the intervals between the penetration depths of the dental burs are relatively small. For example, in some embodiments, the intervals are about 1 mm, potentially reducing the risk of perforating the membrane and/or increasing the practitioner's ability to control the drilling progress.

Alternatively or additionally, the procedure optionally includes forming an access path to the sinus membrane by using an un-sharp and/or un-pointy dental bur(s) with an ascending order of diameter.

In some embodiments, the procedure includes pushing the sinus membrane in steps, by using a sinus elevator(s) (e.g., an osteotome) with a limited penetration depth, in ascending order of length. This has the potential advantage of minimizing the risk of damaging the sinus membrane during the elevation thereof and/or minimizing the risk of over-seperating the sinus membrane.

In some embodiments, the procedure includes stepped filing of the formed access path with a bone graft. The stepped filing comprises introducing bone graft in several portions. Each portion is pushed into the access path using an introducer(s) (e.g., osteotome) with limited penetration depth, in descending order of lengths. This has the potential advantage of minimizing the risk of damaging the sinus membrane while filing the access path, in addition to potentially improving the uniformity and/or density of the filling. It should be appreciated, that the procedure can be performed with fewer than all acts being stepped, for example, drilling and/or lifting and/or filling may be stepped or unstopped.

An aspect of some embodiments of the invention relates to forming a separated bone portion of a jaw that protects underlying soft tissues. In some embodiments a separated bone portion of the crestal bone prevents and/or reduces contact with the sinus membrane during a sinus lift procedure on a patient, using a crestal approach. This is achieved by elevating the sinus membrane by pushing a separated portion of the crestal bone which is adjacent to the sinus membrane. Pushing the sinus membrane by contacting the adjacent separated portion of bone instead of contacting the exposed sinus membrane has the potential advantage of reducing the risk of sinus membrane perforation.

In some embodiments, the separated bone portion is formed when the crestal bone is penetrated. In some embodiments, if the last step of drilling the access path is performed using a concave dental bur, a bone portion that fits with a rim of the concave front surface is detached from the crestal bone and remains adjacent to the sinus membrane. This bone portion is surrounded by a ring of an exposed sinus membrane, revealed by the contact with the rim of the concave contact surface. In some embodiments, if the crestal bone is not too high and if the formed access path is relatively wide, the bone portion surrounded by the exposed sinus membrane can be directly viewed. Viewing the separated bone portion allows for confirming the crestal bone penetration and potentially prevents over-drilling.

In some embodiments, a bone graft is pushed into the crestal access path against the separated bone portion. The presence of the separated bone portion reduces the contact of the bone graft with the sinus membrane, having the potential advantage of reducing damage to the sinus membrane while filing the access path. In addition, the presence of the separated bone portion with the bone graft potentially encourages bone regeneration.

An aspect of some embodiments of the invention relates to performing a sinus lift procedure on a patient using a crestal approach, even in cases of low crestal bone height of 4mm and less, for example a low crestal bone height of from about 2mm to about 4mm, optionally form about 1mm to about 4mm, optionally from about 0.5mm to about 4mm, for example 4mm, 3.5mm, 3mm, 2.5mm, without exposing the lateral wall. In some embodiments of the invention, the method differentiates between cases of initial crestal bone height of 4mm and above, where a single stage procedure may be used, at the end of which the implant is introduced simultaneously with the bone graft, and cases of initial crestal bone height of 4 mm and less, where a multi-stage procedure may be used, with an implant optionally implanted at the end of the second stage. In some embodiments of the invention, damage to the sinus membrane is reduced through the use of a non-sharp and/or non-pointy bur, and/or small steps in advancing the bur and/or via detection of penetration to the sinus membrane by an abrupt change in resistance to axial movement.

In some embodiments of the invention, a one stage procedure comprises: a. Drilling an osteotomy site using a bur connected to a drilling device. In some embodiments, the drilling is done gradually by using the second set of heads in increased sequence of lengths. b. Performing sinus lifting gradually, optionally, by using osteotomes with flat contact surface in increased sequence of lengths c. Filling the osteotomy with bone graft, gradually, by introducing the bone graft into the osteotomy in portions and pushing it into the sinus cavity using osteotomes in a sequence of decreasing lengths. d. Introducing the implant.

In some embodiments of the invention, a two-stage procedure comprises: a. Drilling an osteotomy site using a bur connected to a drilling device. In some embodiments, the drilling is done gradually by using the first set of heads in increased sequence of lengths. b. Performing sinus lifting gradually, optionally, using osteotomes with flat contact surface in increased sequence of lengths c. Filling the osteotomy with bone graft gradually, by introducing the bone graft into the osteotomy in portions and pushing it into the sinus cavity using osteotomes in a sequence of decreasing lengths. d. Letting the site heal for 4-6 months. e. Re-evaluating of the crestal bone height. f. Drilling an osteotomy site using a bur connected to a drilling device, gradually by using the second set of heads in increased sequence of lengths. g. Performing more sinus lifting if needed. h. Filling the osteotomy with bone graft gradually, optionally, by introducing the bone graft into the osteotomy in portions and pushing it into the sinus cavity using osteotomes in a sequence of decreasing lengths. i. Introducing the implant.

In some embodiments of the invention, additional bone thickness is provided by implanting bone or bone growth enhancing elements (e.g., bone chips) at a crestal side of the treatment site, for example, using methods known in the art.

Some examples of non-sharp and/or non-pointy surfaces for the bur head include flat, concave and truncated cone. Optionally, any forward facing edges are rounded.

In some embodiments of the invention the method is being performed using multiple bur types, for example, a cone or rounded or sharp tip when far from the sinus (which may allow for faster penetration through bone) and changing to a flat or concave tip (which is non-sharp and/or non-pointy) when closer to the sinus. In some embodiments, the kit contents reflect this. One potential advantage of the kit, at least in a first set of burs, including only non- sharp and/or non- pointy tips, is that it can make the same kit usable and safe for multiple sub-5 mm situations.

In some embodiments of the invention, the procedure is performed using a set of dental burs consisting of heads of the same diameter, in an increased sequence of lengths.

In some embodiments of the invention, the procedure is performed using a set of dental burs consisting of heads of different diameters, in an increased sequence of lengths and increased sequence of diameters.

In some embodiments of the invention, the procedure is performed using a set of dental burs consisting of heads of different diameters, in an increased sequence of lengths and decreased sequence of diameters.

In some embodiments of the invention, a filler material such as bone graft bone cement, support material, etc. or mixtures of fillers used for sinus lifting, for example, a Bond Apatite cement. A potential advantage of Bond Apatite cements is that the graft resorbs and regenerates the bone, and transforms completely into a vital bone after the healing period. A potential benefit being that when/if a second stage of drilling is required, there is no risk of dispersing residual graft as can be with other types of bone grafts that do not transform completely into a vital bone.. Additionally, or alternatively, a bond graft of the same type as the Bond Apatite cement can be used, such as but not limited to Autogenous graft and calcium sulfate without any adjustments to the procedure.

Additionally or alternatively, a filler material of the kind that do not transform completely into vital bone can be used as well, optionally with an adjusted period of healing period. In some embodiments of the invention, in cases of initial crestal bone height of 4mm and above (for example 4mmm, 5mm, 6mm, 7mm, etc.) a one stage procedure is performed without the need for a second stage of drilling, which may increase the range of suitable bone graft materials.

In some embodiments of the invention a bone regeneration can be achieved with no filler material, with the need of mechanical support such as a sponge or piece of degradable matter. In some embodiments of the invention the filler material can be inserted only to the sinus cavity remining the access path opens for receiving an implant.

A potential advantage of filling both sinus cavity and access path with filler material is to ensure tight filling of the filler material in the sinus cavity and next to the sinus membrane.

In some of the embodiments of the invention filler material can be inserted at the crestal side and/or in the sinus side.

An aspect of some embodiments of the invention relates to detecting when crestal bone is penetrated during the preparation of an osteotomy site, based on an abrupt reduction in resistance. Without being bound to theory, before reaching penetration, a flat head (or concave) pushes against the bone over its entire width. Once the sinus is penetrated, there is an abrupt reduction in resistance to axial advancing, as the bone is expected to be penetrated into the sinus over a significant portion of the head surface. In some embodiments, a user may tactically detect this abrupt change and use it as a signal to stop advancing the bur and/or turn it off. In some embodiments, such a reduction can also be detected by an automated system. Optionally, such system comprises a force or pressure sensor positioned in the motor of the drilling device, which detects when the axial resistance changes abruptly and turns off the rotation of the bur. In some embodiments, at the last stages of drilling with a non-sharp and/or non-pointy dental bur, the rotation of a non-sharp and/or non- pointy dental bur causes an increase in drilling temperature due to the friction, so a liquid irrigation is optionally used for avoiding necrosis of the bone. In some embodiments, the combination of relatively large area of grinding with non-sharp and/or non-pointy dental bur and liquid irrigation causes the last bit of bone between the distal surface of the head of the dental bur and the sinus membrane, to change state from solid to a more soft state, for example a paste. Such a paste is possibly (more) easily evacuated.

In some embodiments, a potential advantage of using non-sharp and/or non-pointy burs is to cause this change in state in the last part of the bone during drilling to potentially further avoid damaging the sinus membrane.

A potential advantage of using a head with concave distal surface is that at the last stage of drilling, the rim of the concave distal surface come in contact with the sinus membrane while a thin layer of bone remain capture between the inner portion of the distal surface of the head and the sinus membrane. The thin layer of bone is pushed with the sinus membrane into the sinus cavity, and promote bone growth after bone graft filling.

In some embodiments, the indication of reduction in friction, optionally together with the use of a distal flat contact surface and the distance limiting stoppers, potentially reduces the risk of the sinus membrane perforations and over drilling.

In some embodiments, the degree of abrupt change optionally depends on the percentage of the distal surface which is not sharp. For example, if 50% or more of the distal surface is flat or concave, such an abruptness may be detected, even in a truncated cone or rounded tip bur. Preferable percentage of the distal surface which is not sharp is 80%, since the edge effects is negligible, and there is no significant portion of the head protruding into the sinus cavity jeopardizing the integrity of the sinus membrane.

A potential advantage of using a concave tip is that abrupt change in resistance happens when the rim penetrates to the membrane, separate a section of bone from the maxillary bone, while most of the head has not penetrated yet. This may increase the abruptness and/or reduce the risk of damage to the membrane.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

Referring now to Fig. 1 showing a flow chart describing an exemplary method for performing a maxillary sinus lifting procedure, using an intra-crestal approach, without exposing the lateral wall of the crestal bone, in patients diagnosed with low crestal bone height of 4mm and less, according to some exemplary embodiments of the invention.

Without being bound to theory, loss of the posterior maxillary teeth can cause an expansion and pneumatization of the maxillary sinus cavity, located in the posterior part of the maxilla, leading to a loss of the residual sub-sinus crestal bone height. Common practice is that where this reduction of sub-sinus crestal bone height is of 4mm or less, there is no sufficient residual bone height for placing an implant with of adequate primary stability

At 100, the crestal bone height of a patient is diagnosed, for example, using CBCT (Conebeam computed tomography). In some embodiments, a patient will be found suitable for treatment in cases of crestal bone height of about 4mm or less at a potential implant location in the upper jaw; for example in cases of crestal bone height of from about 2mm to about 4mm, optionally form about 1mm to about 4mm, optionally from about 0.5mm to about 4mm, for example 4mm, 3.5mm, 3mm, 2.5mm.

At 102 a vertical sub-sinus osteotomy procedure is performed. In some embodiments, an access path to the sinus cavity is drilled through the extraction socket, using a dental bone bur mounted on a dental drill. This is in contrast to common practice where lateral access to the sinus is used.

At 104 lifting of the sinus membrane is performed. In some embodiments, a sinus cavity, between the membrane and the bone, and optionally the access path thereto, is filled with support material. Optionally, the support material is bone graft or bone matrix material, which ossifies to form new bone. During the filling of the sinus cavity with bone graft, the bone graft is spontaneously expending to the sides of the cavity, to achieve an area of total width greater than the width of the drilled access path. For example, for an access path with width of about 3 mm to 4 mm, the final width of the sinus cavity after being filled with bone graft is about 7-8mm. At 106, optionally, the clinician assesses if the initial crestal bone height is sufficient for introduction of an implant immediately (e.g., same day or within a week) after performing 104. In some embodiments, a sufficient bone height is, for example, of above about 10mm according to the length of the desirable implant. Optionally above from about 8mm to about 12mm, optionally from about 6mm to about 15mm, optionally from about 6mm to about 20mm.

If not, at 107 the site is optionally allowed to heal for a bone consolidation period. At that time, steps 100-106 may be repeated if needed.

At 108, an implant is optionally is introduced into the bone at the treatment location, optionally reusing the access path created for accessing the sinus.

Referring now to Fig. 2A showing a schematic side view of a dental bur 200 comprising an elongated shaft 202 and a head 204, according to some embodiments of the invention. In some embodiments, an exemplary dental bur 200 comprises an elongated body comprising a distal end and a proximal end. In some embodiments, at distal end, the dental bur 200 comprises a head 204. In some embodiments, extending proximally form the head 204, the dental bur 200 comprises an elongated shaft 202, which extends until the proximal end of the dental bur 200. In some embodiments, the head 204 comprises a distal surface. In some embodiments, head 204 has a flat distal surface 208. In some of the embodiments, head 204 is shaped as a cylinder of fixed length 216 and width 214. In some embodiments, the dental bur 200 comprises a stopper 206 positioned between the head 204 and the elongated shaft 202. In some embodiments, the stopper 206 is configured to stop the advancement of the dental bur 200 during the drilling action. In some embodiments, shaft 202 optionally terminates at a proximal distal end thereof with a standard connection 203 (e.g., in the form of a flat section and a notch) to a dental drill, when dental bur 200 is in used.

In some embodiments, dental bur 200 is optionally arranged, from proximal to distal: connector 203, elongated shaft 202, stopper 206, head 204 and distal flat surface 208.

In some embodiments of the invention, dental bur 200 is used for dental drilling of an access path 220 to a maxillariy sinus cavity 222 through a crestal bone 224 until reaching a sinus membrane 226, as part of a maxillary sinus lifting procedure (shown for example in Figs. 2C-2D).

In some embodiments, flat distal surface 208 of head 204 of dental bur 200, is first to interact with crestal bone 224 and grinding it uniformly at a constant width 214 according to a specific bur used, from the first contact of flat distal surface 208 of head 204 with the crestal bone 224. In some embodiments, formed access path 220 is shaped as a cylinder of pre-determined depth 228 and width 230 according to a length 216 and a width 214, of head 204, respectively. In some embodiments, at the point of crestal bone penetration, the flat distal surface 208 of head 204 of dental bur 200 is desirably substantially tangent to sinus membrane 226 without protruding into sinus cavity 222, at least not as a sharp long object, for example, not as a pointy object, and potentially avoiding over-drilling and damaging sinus membrane 226. In some embodiments, at this time, flat distal surface 208 of head 204 of dental bur 200 pushes axially (vertically) against sinus membrane 226 and, at the final stages of drilling when almost reaching the sinus membrane, a residue of crestal bone 224 changes its consistency from a solid consistency to a mushy creamy consistency. In some embodiments, the combination of grinding relatively large area with flat distal surface 208 of head 204 with liquid irrigation causes the change in consistency. In some embodiments, if the drilling is not stopped, the dental bur detaches the sinus membrane 226 from the crestal bony wall. Optionally, this detaching is substantially uniform, with reduced risk of sinus membrane perforation (shown for example in Fig. 2D).

In some embodiments, drilling crestal bone 224 at constant width using distal flat surface 208, until penetration into sinus cavity 222, is potentially reflected in an abrupt reduction in drilling resistance, which indicates to the clinician to stop the drilling procedure, and preventing over drilling of sinus membrane 226 after crestal bone 224 penetration has been achieved.

In some embodiments, stopper 206 comprises a width greater than the width 214 of head 204, for example from about 1mm to 4mm greater, optionally from about 0.5mm to 5mm greater. In some embodiments, when stopper 206 reaches the bone, further advance of head 208 is prevented and progress of the drilling is restricted. In some embodiments of the invention, when dental bur 200 comprises the stopper 206, the depth 228 of drilled access path 220 is determined by the length 216 of the head 204.

In some embodiments of the invention, the stopper 206 is fixed and the length 216 of head 204 is constant. Alternatively, the stopper 206 is movable and can move along the head 204, altering the effective drilling depth. Optionally, the stopper is a radial extension to a sheath that covers an elongate drill head. In some embodiments, when retracted, a greater exposed length 216 of head 204 is exposed (as shown for example in Fig. 2F). In some embodiments, the dental bur 200 is a one-piece unit with fixed or dynamic stopper 206, or a two-piece unit with removable stopper 216, fixed or dynamic.

Referring now to Figure 2B showing a schematic side view of dental bur 200b, which is a variant of dental bur 200, shown in Fig. 2A, having a head 204 with a concave distal surface 210, according to some embodiments of the invention.

In some embodiments, during use, concave distal surface 210 is first to interact with crestal bone 224 and in particular, the rim of concave distal surface 210 is first in contact with crestal bone 224. A potential advantage of forming access path 220 to sinus cavity 222 using dental bur 200b of head 204 of concave distal surface 210 is that the drilling resistance is reduced compared to the drilling resistance of head 204 of flat distal surface 208. Another potential advantage of using a concave leading surface is that only the rim penetrates into sinus cavity 222. In some embodiments, such penetration can result in a more abrupt change in axial resistance than a flat surface.

An additional potential advantage, of dental bur 200b of head 204 of concave distal surface 210 is when contacting with sinus membrane 226 to detach it from the bony crestal wall. In some embodiments, optionally, only the rim of concave distal surface 210 come in contact and pushes sinus membrane 226, which may further minimize the risk for sinus membrane perforation

An additional potential advantage of dental bur 200b of head 204 of concave distal surface 210 is an improved adaptation to the surface of un-flat or convex bone.

Referring now to Figs. 2E-G showing a schematic illustration of a dental bur with an adjustable stopping distance, in accordance with some embodiments of the invention. Fig. 2E is showing a dental bur 200 comprising a head 204 and a shaft 202 without a stopper 206. Figs. 2F- G are showing a dental bur comprising a head 204 a shaft 202 and an adjustable stopper 206, continuously adjusted using a thread 207 on which stopper 206 is mounted such that rotation relative thereto causes stopper 206 to advance distally or retract proximally.

Referring now to Figs. 2H-J showing a schematic illustration of a dental bur with an adjustable stopping distance, in accordance with some embodiments of the invention. Fig. 2H is showing a dental bur 200 comprising a head 204 and a shaft 202 without a stopper 206. Figs. 2I-J are showing a dental bur comprising a head 204 a shaft 202 and an adjustable stopper 206 with a locking mechanism, that when actuated causes stopper 206 to advance distally or retract proximally.

In some embodiments of the invention the length 216 of the exposed head can be marked by lines or numbers on the stopper 206 (as shown in Figs. 2E-J), or by lines or numbers on the shaft 202, in order to represent the length of the exposed head 204. Figs. 2F and 21 are showing a relatively greater exposed length 216 of head 204 compared to Figs. 2G and 2J.

Referring now to Figs. 2K-2P showing examples of head 204 of dental bur 200/200b according to some of the embodiments of the invention. In Fig. 2K head 204 is shaped as a truncated cone 218 with a flat distal surface 208. In Fig. 2L head 204 is shaped as a cylinder 212 with leading cutaway corners 219 and a flat distal surface 208. In Fig. 2M head 204 is shapes as a truncated cone 218, where a leading surface is a concave distal surface 210. In Fig. 2N head 204 is shaped as a cylinder 212 with an upper truncated cone 218 and a concave distal surface 210. In Fig. 20 head 204 is shaped as an upside-down cone 217 with a flat distal surface 208. In Fig. 2P head 204 is shaped as an upside-down cone 217 with concave distal surface 210.

Referring now to Figure 3A showing a perspective top view of head 204 in accordance with some of the embodiments of the invention. In some embodiments of the invention, head 204 is formed of a rigid material, such as stainless steel. In some embodiments, head 204 is covered with an abrasive material, such as diamond grains. In some embodiments, other designs can be used as well, for example, a tungsten tip with metal projections or a metallic tip with a carbide abrasive coating.

Figure 3B shows a perspective top view of a head 204 with a concave surface 210, in accordance with some of the embodiments of the invention.

In Figures 3A-B a diamond coating potentially provides head 204 with the ability to grind hard tissues and bones, such as crestal bone 224 and the grit size of the diamond coating is appropriate to osteotomy drilling for a sinus lifting procedure. It is known in the art that there is different nomenclature for classifying grit sizes. For example, fine, medium, medium plus and rough. A grit size classified as fine can be used but it may require long drilling period and/or applying massive force. A grit size classified as rough is not suitable since there is a risk of membrane perforation. A grit size classified as medium or medium plus is preferred for effective drilling without risking the membrane integrity.

In some embodiments, the rigid material from which head 204 is made can be stainless steel, milled as one unit and covered by diamonds grains.

Referring now to Figure 4A showing a dental kit 400 comprising dental burs 200, an optional sinus membrane lifter, and an optional bone carrier, in accordance with exemplary embodiments of the invention. In some embodiments, optionally, a dish 401 for placing a bone graft is provided as well.

In some of the preferred embodiments of the invention, the sinus membrane lifter is an osteotome 402. Optionally or additionally, the bone carrier is a bone carrier syringe 403. In some embodiments, the dental kit 400 comprises several dental burs 200 of different lengths 216 of head 204 with stopper 206, as shown in Fig 4B, for example of the type described with reference to Figs 2A-K and 3A-B. In some of the embodiments of the invention, the dental kit 400 comprises dental burs 200 of uniform head 204, of flat distal surface 208 or concave distal surface 210, with different lengths 216.

In some embodiments of the invention, the dental kit 400 comprises a combination of burs

200 of head 204 of flat distal surface 208 and concave distal surface 210. In some embodiments of the invention, the dental kit 400 comprises a combination of burs 200 of head 204 of flat distal surface and/or concave distal surface with head 204 of pointy or prominent distal surface, such as conic and/or round shaped heads.

A potential advantage of using a combination is providing the clinician the ability to manipulate drilling resistance, at the various steps of the drilling procedure, by selecting the appropriate design of head 204. Head 204 of pointy or prominent distal surface first contact crestal bone 224 with the tip of the surface, and grinding the bone gradually until reaching the maximum width of head 204, so the resistance to drilling is increased compared to head 204 shaped as a cylinder 212. Potentially, head 204 of pointy or prominent distal surface may be in used at the first steps of drilling, before approaching sinus membrane 226.

In some embodiments, osteotome 402 optionally comprises a shaft 404, an active part 406 with length 408, a distal contact surface 410 and a stopper 412. According to some of the preferred embodiments of the invention distal contact surface 410 is flat and/or smooth and/or rounded. In some embodiments, the edge 411 of contact surface 410 is smooth as well. According to some of the preferred embodiments of the invention, stopper 412 is a dynamic stopper that can limit the exposed active part of the osteotome. In some embodiments length 408 is ranged from about 1mm to about 15mm, in intervals of 1mm. In some embodiments of the invention, stopper 412 is continuously adjusted using a thread 413 (schematically shown in Fig. 4C) on which stopper 412 is mounted such that rotation relative thereto causes stopper 412 to advance distally or retract proximally. Alternatively, the osteotomes are a set of 15 osteotomes of fixed length from 1-15 mm, in intervals, for example, of 1 mm. Optionally, the osteotomes are a set of 30 osteotomes of fixed length from 0.5-15mm, in intervals of 0.5mm. Optionally, the osteotomes are a set of multiple osteotomes of fixed length from 0.5-15mm, in combination of intervals of 0.5mm and 1mm.

In accordance with some of the exemplary embodiments of the invention, dental kit 400 is provided for performing an intra-crestal maxillary sinus lift procedure. In some of the embodiments of the invention dental kit 400 comprises two sets of dental burs 200. In some embodiments, a first set comprising dental burs 200 with heads 204 of length 216 from l-5mm, and width 214 from 3.5- 5mm, and a second set comprising dental burs 200 with heads 204 of length 216 from 6-10 mm, and diameter from 3-3.5 mm.

In some embodiments the outer diameter of bone graft carrier syringe 403 is larger than the diameter of access path 220, allowing the introduction of bone graft into access path 220 through the opening thereof while preventing penetration of bone graft carrier syringe 403 thereinto. This has the potential advantage of reducing and/or preventing injury of the sinus membrane by bone graft carrier syringe 403. An additional potential advantage is minimizing leakage of bone graft along the sides of syringe 403. In some embodiments of the invention, the tip of syringe 503 is conical and with a short length, such as less than 3 mm or less than 2 mm, and sized so that the distal end of the tip fits into the crestal path, while the body of the tip seals the crestal path and avoids leakage.

In some embodiments, the outer diameter of bone graft carrier syringe 403 is about 4.5 mm. Since the second set comprises dental burs with diameters from 3-3.5 mm, the formed access path may be for example with an opening of 4 mm so that bone graft carrier syringe 403 is obstructed from entering into the access path.

In some embodiments, dental kit 400 comprises one or more additional bone graft carrier syringe(s), with a larger diameter than bone graft carrier syringe 403, Since the first set comprises dental burs with diameters from 3.5-5.5 mm. For example, the formed access path may be for example with an opening of 4.5 mm so that an additional bone graft with a diameter of 5 mm can be used and obstructed from entering into the access path.

In some embodiments, dental kit 400 comprises a set of bone graft carrier syringes, with different outer diameters, optionally, for adjusting the bone graft carrier syringe 403 to the opening size access path 220. For example, a plurality of bone graft carrier syringes each having a different diameter in the range of 4-6 mm.

In some embodiments, bone graft carrier syringe 403 comprises a stopper at its distal end, which comes in contact with the crestal bone. In some embodiments, the stopper is shaped as a ring that encircles an opening at the distal end of graft carrier syringe 403. The outer diameter of the ring is larger than the diameter of access path 220 such that the crestal bone obstructs the distal end of graft carrier syringe 403 from entering thereinto. In some embodiments, the stopper is used for relatively wide access paths 220.

In some embodiments, the second set of dental burs 200 of dental kit 400 is optionally used in a procedure at which an implant is been introduced at the end of the procedure. Optionally, width 230 of access path 220 to sinus cavity 222 should be smaller than the width of the implant to assure sufficient friction during implant insertion. In some embodiments of the invention width 230 of access path 220 should be smaller than the width of the implant by about 1mm, for example by 0.5mm, optionally by 1.5mm, optionally by 2mm, optionally, between about 1mm and about 1.5mm, optionally, between about 0.5mm and about 2mm, and can be adjusted according to the bone density.

In some embodiments of the invention, width 216 of head 204 of dental burs 200 of the second set of dental kit 400 is restricted according to the width of the implant. Optionally, the implant is provided with the kit or is matched up using a coding/categorization scheme. In some embodiments, the first set of dental burs 200 of dental kit 400 is optionally used in a procedure of sinus lifting, at which access path 220 to sinus cavity 222 has been closed without the insertion of an implant, by introducing a bone graft and waiting for bone consolidation. In some embodiments, width 230 of access path to sinus cavity 222 (during the drilling using the first set) is not restricted by the width of the implant.

In some embodiments, a procedure with closing before implanting is optionally done in cases of low residual crestal bone of 4 mm or less, so width 230 of access path 220 to sinus cavity 222 is optionally made greater than the expected width of the implant (or apical tip thereof) to ensure sufficient width of crestal bone 224 after bone consolidation, for further implant insertion.

In some embodiments, optionally, width 216 of head 204 of dental burs 200 of the first set of dental kit 400 is of greater width compared to the second set and in accordance with a desirable width of crestal bone 224 after bone consolidation.

In some embodiments of the invention, a relatively wide access path 220 to sinus cavity 222 may be prefers since it provides more flexibility to lifting sinus membrane 226 during the lifting procedure and minimize the risk of membrane tearing. A potential advantage of performing drilling of access path 220 of width 230 according to the width 214 of a first set of dental burs 200 comprising heads 204 with diameters of 3.5-5 mm, is that a narrower or wider heads 204 may jeopardize the integrity of the membrane during drilling and/or sinus lifting. This may be a greater consideration at the first lifting as compared to subsequent lifting. This is another potential reason for preferring that the width of the first set of burs have a larger width 214 compared to the second set. It is also noted that the second set may be used for greater drilling depth, a greater width may mean more difficulty (and heat) while drilling, with a flat head, particularly, in cases of initial crestal bone height of about 4 mm and above, when a one-stage procedure is performed and grinding is done on a mature and compact bone.

Referring now to Figures 5A-C showing a flow chart of an exemplary method for preforming maxillary sinus lift procedure on a patient using the crestal approach, according to some embodiments of the invention.

Referring also to Figures 6A-J schematically showing schematic representations related to an osteotomy procedure, as described in Figs. 5A-C. In some embodiments, the osteotomy procedure is performed by using dental kit 400 consisting of a set of dental burs 200 shaped as a cylinder 212 of flat distal surface 208, in accordance with some of the exemplary embodiments of the invention. In some embodiments, dental kit 400 comprises additional components (as shown for example in Fig. 4 A) Referring also to Figgures 7A-I showing schematic representations of stages of maxillary sinus floor elevation, via intra-crestal approach, in accordance with some embodiments of the invention, and as described in Figs. 5A-C.

At 500 a patient with a potential implant location in an upper jaw adjacent sinus cavity 222 is first selected by the clinician for performing osteotomy drilling trough the extraction socket.

At 502 the height of crestal bone 224 is evaluated using CBCT, to determine if a one stage procedure or a two-stage procedure is required. In cases of crestal bone height of a 4 mm and above a one stage procedure is required. In cases of crestal bone height of 4 mm or less a two- stage procedure is required, as shown for example in Figs. 21A-B showing a CBCT of a crestal bone with an initial height less than 4 mm.

At 504 the crestal bone is exposed through the extraction socket (as shown for example in Fig. 21D), at a potential implant location, as shown for example in Fig. 6A and Fig 21C. Residual crestal bone 224 of low bony level is adjacent to sinus cavity 222, and a designated location for drilling 600 access path 222 to reach sinus membrane 226 is selected.

Employing a vertical approach to expose the crestal bone through the extraction socket has the potential advantage of minimizing the invasiveness of the procedure. In some embodiments a “full-thickness flap” is performed (reflecting a section of the soft tissue, for exposing the underlying crestal bone), as shown in Fig. 19. In some embodiments, the full-thickness flap is performed by creating an incision near the center of the crestl bone ridge, at a portion thereof closer to the palate, the incision is then extended away from the palate. This incision which is distal from the gum (gingiva) has the potential advantage of reducing the patient’s discomfort and/or pain. In addition, since a single flap is required to expose the bone, the patient's recovery period is potentially shortened. This technique of exposing the crestal bone potentially allows visualization of the underlying crestal bone, which potentially allows the clinician to oversee the progress of the procedure and has the potential advantage of increasing the safeness of the procedure.

At 506 the clinician chooses a set of dental burs 200, according to the initial crestal bone height. In cases of crestal bony level of 4 mm and above, the suitable set is the first set of dental kit 400, comprises heads 204 of 1-5 mm with diameter that can be from 3.5-5 mm, for a one stage procedure, or for the second stage of two-stage procedure. In cases of crestal bony level of 4 mm and less, the clinician should use the entire kit for a two-stages procedure, first the second set of dental kit 400, comprises heads 204 of 6-10 mm with diameter that can be from 3-3.5 mm, for the first stage, and then, the first set, for the second stage.

At blocks 508-515 a gradual osteotomy procedure is performed using a set of dental burs 200 with heads 204 of the same width 214 and in an increased sequence of lengths 216, in

RECTIFIED SHEET (RULE 91) accordance with some of the preferred embodiments of the invention, as shown for example in Figs. 21E-H.

In some embodiments of the invention the procedure is performed using a set of dental burs 200 with heads 204 of different widths 214, in an increased sequence of lengths 216 and increased sequence of widths 216. A potential advantage of such sequence is a decreased resistance during the drilling procedure, compared to drilling with heads 204 of uniform width 214. The resulted access path 220 is at the same uniform shape of a cylinder, determined by the width of the final and longest head 204.

In some embodiments of the invention the procedure is performed using a set of dental burs with heads of different diameters, in an increased sequence of lengths and decreased sequence of diameters. A potential advantage of such sequence may be beneficial for drilling an access path of gradual width 230 according to the shape of some implants in order to increase the friction of implant insertion and better the primary implant stability.

In more detail, at 508 the first step of drilling an access path 220 to sinus cavity 222 is performed using dental bur 200 with head 204 of shorter length, as shown for example in Figs. 6B-C and in Figs. 21E-F. According to some of the embodiments of the invention the shorter head is of length of 1 mm.

In some embodiments, the length differences between the dental burs are uniform, for example, each subsequent head 204 is longer than the one preceding it by a fixed increment, for example by 1 mm. Alternatively or additionally, the length differences between the dental bur’ s heads are in descending order, allowing progress in large steps at the beginning of drilling, while reducing the steps as approaching close to the bone.

In some embodiments, the shorter head is longer than 1 mm, and the length thereof is selected according to the initial crestal bone height of the patient. For example, a crestal bone with an initial height of about 5 mm can be first drilled by a 3 mm long head 204, and then the drilling continues with heads longer by 1 mm at each step. This has the potential advantage of simplifying the procedure while still reducing the risk of damaging the sinus membrane.

In Fig. 6B first dental bur 200 with stopper 206 and head 204 of flat distal surface 208, is first come in contact with crestal bone 224, at the designated location for drilling 600, according to some of the embodiments of the invention.

In Fig. 6C the first head 204 of length 216 of 1 mm, according to some of the embodiments of the invention, is fully occupied access path 220 when stopper 206 is contacting crestal bone 224, at the end of the first step of drilling. At 510 stopper 206 of the first dental bur 200 reaches and contact crestal bone 224 and stopes the progress of the drilling, as shown for example in Fig. 6D and in Fig. 2 IE).

In some embodiments, the first dental bur 200 is removed to reveal access path 220 after the first step of osteotomy procedure. Access path 220 is shaped as a cylinder (as shown for example in Fig. 2 IF) with a depth 228 and a width 230 according to length 216 and width 214, of first head 204. In some embodiments, width 230 (of access path 220) is wider than width 214 (of head). This difference may be a result of head 204 runout during rotation, and/or as a result of the drilling techniques employed by the clinician (such as pressure applied, selected speed of the drill, and/or the duration of drilling). For example, drilling with dental bur(s) having head(s) 204 with a diameter of 3.5 mm can result in access path 220 having a width 230 of about 4 mm. Use of a fixator at the distal surface of the bur may reduce this difference.

At 512 the next step of the osteotomy drilling is performed using a dental bur with a head longer from the head used in the previous step. According to some of the embodiments of the invention the head is longer by 1 mm from the head of the previous step, as shown for example in Fig. 6E. In some embodiments, the second head 204 longer from head 204 used in the previous step is fully occupied access path 220 when stopper 206 is contacting crestal bone 224, at the end of the second step of drilling.

At 514 the stopper of the dental bur reaches and contact the crestal bone and stops the progress of the drilling, as shown for example in Fig. 6F and Fig. 21G. In some embodiments, the second dental bur 200 is removed to reveal access path 220 after the second step of the osteotomy procedure. In some embodiments, access path 220 shapes as a cylinder with a depth 228 and a width 230 according to length 216 and width 214 of second head 204, for example, a length and width of 2mm, for example, a length of about 2mm and a width of about 3.5mm, optionally a length of about 2.5mm and width of about 5mm, optionally length of about 1.5mm to about 2.5mm, and a width of about 3.5mm to 5mm, optionally a length of about 1mm to about 4mm, and a width of about 2mm to 6mm.

At 515 as long as the clinician does not sense a change in the drilling friction, the drilling of access path 220 through crestal bone 224 continues using a dental bur with a longer head, each time a bur is introduced into the osteotomy site. According to some of the embodiments of the invention, the length of the head of the dental bur increased in intervals of 1mm, as shown for example in Figs 6G-H.

In Fig. 6G the penultimate step of drilling is performed using a dental bur 200 with head 204 of increased length according to the number of drilling steps. In some embodiments, head 204 fully occupies the access path 220 when stopper 206 contacts crestal bone 224, at the end of the penultimate step of drilling. In some embodiments, access path 220 shaped as a cylinder with a depth 228 and a width 230 according to length 216 and width 214 of penultimate head 204.

In Fig. 6H penultimate dental bur 200 is removed to reveal access path 220 after the penultimate step of the osteotomy procedure. Access path 220 shaped as a cylinder with a depth 228 and a width 230 according to length 216 and width 214, of penultimate head 204.

At 516 the clinician assesses if a reduction in drilling friction was felt, which indicates bone penetration. According to some of the preferred embodiments of the invention, the drilling procedure is performed using dental bur 200 with head 204 shaped as a cylinder of flat distal surface 208, that pushes vertically the crestal bone while there is a balance between the compressive force applied by the clinician and the hardness of the bone, and a cylinder shaped opening is formed (as described in Figs. 6D, 6H). At the point of bone penetration, the head of flat distal surface come in contact with the sinus membrane, at once, as shown for example in Figs. 61 and 7A, and detaches it from the bony crestal wall, uniformly an vertically, at once, and the clinician will fill an abrupt reduction in drilling friction.

In Fig. 61 the ultimate step of drilling is performed, using dental bur 200 with head 204 of ultimate length 216.

Ultimate head 204 fully occupies access path 220 when stopper 206 is contacting crestal bone 224, at the end of the penultimate step of drilling. Access path 220 is shaped as a cylinder with a depth 228 and a width 230 according to length 216 and width 214 of ultimate head 204. At the penetration of the crestal bone, flat distal surface 208 of head 204 of dental bur is tangent to sinus membrane 226 without protruding into sinus cavity 222 and avoiding over-drilling of sinus membrane, then, flat distal surface 200208 of head 204 of dental bur 200 is pushed 226 vertically against the sinus membrane and detaches sinus membrane 226 from the bony crestal wall, uniformly at one, with minimum risk of sinus membrane perforation.

In Fig. 6J simultimate dental bur 200 is removed to reveal penetrated crestal bone 224 and access path 220 to sinus cavity 222 after the ultimate step of osteotomy procedure. Access path 220 shapes as a cylinder with a depth 228 and a width 230 according to length 216 and width 214, ultimate head 204.

In some embodiments of the invention the indication of abrupt friction drop can be achieved by using dental bur 200 comprises of head 204 of concave distal surface 210.

A potential advantage of the concave contact surface is an improved adaptation to the surface of un-flat or convex bone, alternatively, when the concave contact surface come in contact with the sinus membrane to detached it, only the rim of the concave surface pushes the membrane to further minimize the risk for sinus membrane If the clinician felt the abrupt reduction in milling friction, then (following the letter A to Fig. 5B) at 518 a sinus lifting procedure is performed gradually by osteotomes 402 of flat distal surface 410 with round edges, as described for example at block 104 of Fig. 1, and is shown for example in Figs. 7B-D and Fig. 211. In Fig. 7B, first osteotome 402 of exposed active part 406 of length 408 equal to length 216 of head 204 of final dental bur 200 used for forming access path 220 to sinus cavity 222 is used for lifting sinus membrane 226, according to some of the embodiments of the invention.

Alternatively or additionally, first osteotome 402 can have exposed active part 406 with length 408 longer by 1 mm (for example) than length 216 of head 204 of final dental bur 200 used for forming access path 220.

Once the stopper 412 of the osteotome reaches and contacts crestal bone 240, the sinus lifting is ceased and the next osteotome 402, of length increased by 1mm is introduced to further lift the sinus membrane, as shown in Fig 7D. In order to avoid sinus membrane perforation, the penetration of the osteotome 402 should not exceed the final length 216 of head 204 of the dental bur 200 that was used to create the access path, by more than 3 mm. This may avoid exceeding the flexibility limit of the sinus membrane

At 520 an amount of a bone graft is introduced into the access path 220, by using a carrier apparatus such as bone graft carrier syringe 403, as shown in Fig. 7E. Optionally, the bone graft is loaded into bone graft carrier syringe 403 by scraping the bone graft with the opening at its distal end into bone graft carrier syringe 403.

At 522 the bone graft is pushed into the sinus cavity using the osteotome 402 of the final length that was used to lift the sinus membrane 226.

At 524 the osteotome is removed from the osteotomy site after the stopper of the osteotome reaches the crestal bone.

At 526 additional amount of a bone graft is introduced into the osteotomy site.

At 528 the additional amount of the bone graft is pushed into the sinus cavity using an osteotome shorter by 1mm than the previous, as shown in Fig 7G.

At 529-530, the gradual graft lifting proceeds, in a decreased sequence of lengths, reducing 1mm from the active part of the osteotome each time the osteotome is re-introduced into the osteotomy site until the final osteotome length that is used is 1mm.

If the assessment performed at 530 provides a positive result, which means that the final osteotome used is of 1mm length, then at 532 a final amount of the bone graft is placed at the top of the osteotomy and compacted above, for example as shown in Fig.7F and shown for example in Fig. 21 J. Optionally, in cases of one stage procedure, the bone filling can be only of sinus cavity 222, remaining the access path 220 open for implant insertion.

In some embodiments of the invention, the preferable bone graft of choice is Bond Apatite cement. A potential advantage of the Bond Apatite cements is that the graft resorbs and regenerates the bone, and transforms into a vital bone after the healing period, potentially, when a second stage of drilling is required, there is less and/or no risk of dispersing residual graft as can be with other types of bone grafts that do not transform completely and/or substantially completely into a vital bone. In addition, the Bond Apatite’s transformation into a vital bone has the potential advantage of improving osseointegration (bone ingrowth into the metal implant) which is necessary for the completion of the implantation.

In addition, Bond Apatite cement is a porous substance that absorbs blood relatively rapidly compared to nonporous materials. The absorption of blood causes the material to become softer and potentially less aggressive for the sinus membrane during insertion of the bone graft against the membrane.

The Bond Apatite cements additionally serve as a barrier at the opening of the filled access path and allow the opening to be closed without using a collagen membrane, having the potential advantage of simplifying the procedure.

Additionally, or alternatively, a bond graft of the same type as the bond apatite cement can be used without any adjustments to the procedure, Additionally or alternatively, a bond graft of the kind that integrates into the bone can be used as well, with adjusted period of healing period. Additionally, in cases of initial crestal bone height of 4mm and above a one stage procedure is performed without the need for a second stage of drilling, thus there is no limitation regarding to type of the bone graft used.

At 532 the crest bone level at the end of the two-stage procedure is above 10 mm and the implant is introduced into the osteotomy site.

At 534 the progress of the procedure is determined according to the initial crestal bone height.

Flowchart proceeds following letters B and C in Fig. 5C.

At 536, following the letter C from Fig. 5B, in cases of initial crestal bone height of 4mm and above, the final crest level is above 10mm and the implant is introduced into the access path, at the end of a one-stage procedure.

At 538, following the letter B from Fig. 5B, in cases of initial crestal bone height of 4mm and less, the crest level at the end of the first stage is 4-5mm, and the site is sutured (as shown for example in Figs. 21K-L) and left for healing and for bone consolidation for 4-6 months, as shown

RECTIFIED SHEET (RULE 91) in Fig. 71 and Fig. 21C. At the starting point of the second stage, the initial crestal bone height is above 4mm, and the process is re -preformed to achieve a final crest level above 10mm. Alternatively, other intra-crestal methods can be used at this point when a sufficient crestal bone level of 4mm has been achieved.

At 540 the height of crestal bone 240 is re-evaluated using CBCT (as shown for example in Fig. 21M), for determining the height of the crestal bone at the end of the first stage.

At 542 the crestal bone 240 is re-exposed through the extraction socket, as shown for example in Fig. 21N, and as Act 504 describes.

Optionally, at 544 the clinical selects the first set of dental burs suitable for crestal bony levels of 4mm and above includes heads of l-5mm with a diameter that can be from 3.5-5mm.

Optionally, at 546 a second stage of drilling access path 220 to sinus cavity 222 is performed, gradually, using dental burs 200 with a sequence of increased lengths 216, until the clinical can fill an abrupt reduction in drilling friction, indicates of bone penetration (as shown for example in Figs. 21O-Q, where Fig. 21P is showing a first step of the drilling and 21Q showing the last step of drilling). The designated location for drilling access path 220 of the second stage is at the location of the filed access path of the first stage.

Optionally, at 548 gradually sinus lifting is performed using osteotomes in a sequence of increased lengths.

Optionally, at 550 bone graft is introduced into the access path in steps, and pushed into the sinus cavity by osteotomes in a decreased sequence of lengths. Optionally or alternatively the graft filling can be of the sinus cavity and access path or only of the sinus cavity.

Optionally, at 552 an implant is introduced to the site, and the incision closed, optionally with sutures as shown for example in Figs. 21R-21S. In some embodiments, a follow-up is performed a period (allowing time for osseointegration) after the implantation to confirm that the implant fuses with the surrounding bone.

Referring now to Figs. 8A-8C showing images of part of an osteotomy procedure, in accordance with some exemplary embodiments of the invention.

Fig. 8A shows dental bur 200 with head 204 creating access path 220 as stopper 206 contacts crestal bone 224.

Fig. 8B shows that access path 220 during the osteotomy procedure is shaped as a uniform cylindrical bore, accordance to the shape of cylinder 212 head 204 of dental bur 200.

Fig. 8C shows how path 220 is deepened when a bore with a longer stopping distance is used. This bore reaches the sinus membrane 226 without perforating it.

RECTIFIED SHEET (RULE 91) Referring now to Figure 9A showing a schematic side view of a dental bur 900, having a point extending from a distal surface thereof, in accordance with some of the embodiments of the invention.

Referring also to Figure 9B showing a perspective top view of a head with a point, in accordance with some of the embodiments of the invention.

In some embodiments, a point 902 in the form of an axial elevation, such as a bump and/or a protrusion is positioned on distal surface 904, at the center thereof (e.g., at the center of rotation of head 904). In some embodiments, point 902 potentially reduces undesired movement(s), such as slippage, of dental bur 900 over the bone ridge (e.g., the crestal bone surface which is characterized by elevations and/or depressions along thereof) at the start of drilling.

For example, point 902 potentially reduces runout of the flat and/or concave surface over the bone’ s ridge. This has the potential advantage of reducing the risk of undesired deviations from the designated location for drilling (e.g., designated location for drilling 600 shown in Fig. 6B-I) which might result in misplacement of the access path (e.g., access path 220 shown in Figs. 6A-J) and/or in undesired enlargement of the osteotomy site (e.g., access path) diameter.

In some embodiments, the height of point 902 above the distal face of the bur is about 0.2- 0.5 mm, or 0.1-0.5 mm, or about 0.2 mm, or about 0.3 mm, or about 0.5 mm, or lower or higher or intermediate lengths. A potential advantage of point 902 with a height of about 0.2 mm and no more than 0.5 mm is that there is a reduced risk to impair the sinus membrane if dental bur 900 penetrates the crestal bone (for example if the initial crestal bone is about and/or less than 1 mm)

In some embodiments, point 902 can be mounted on dental bur 200b having a concave distal surface 210, and/or on dental bur 200, having a flat distal surface 208, alternatively or additionally, pointer 902 can be mounted on other dental bur designs, for example, a rounded dental bur.

In some embodiments, point 902 occupies a relatively small surface from the distal surface of the bur, such as flat distal surface 904, so that the presence of point 904 does not impair and/or less impair the properties of the concave and/or flat distal surface (e.g., uniform milling, abrupt reduction in resistance when penetrating the crestal bone). In some embodiments, the surface occupied by point 902 is no more than 10% of the surface of flat distal surface 904. For example, 3% or 5% or 10%, or 3-8%, 5-10%, or lower or higher or intermediate percentages.

Referring now to Figure 10A showing a schematic side view of an embodiment of a dental bur, in accordance with some of the embodiments of the invention.

Referring also to Figure 10B showing a schematic side view of an embodiment of a dental bur’s head, in accordance with some of the embodiments of the invention. Referring also to Figure IOC, showing a cross-section of an embodiment of a dental bur’s proximal end, in accordance with some of the embodiments of the invention.

In some embodiments, exemplary dental bur 1000 comprises a head with a diameter of about 2.8-4 mm. In some embodiments, dental bur 1000 is mounted on a stopper 1006 having a diameter of about 6 mm, where head 1004 and stopper 1006 are concentric. In some embodiments, at least a portion of the front surface of the stopper is concave, having the potential advantage of reducing the risk of head 1004 detaching from stopper 1006. For example, in some embodiments, the front surface of the stopper comprises a flat annular edge and a sloped portion at the center, which descends towards head 1004. For example, stopper 1006 has a slope of 20 degrees toward the center thereof.

In some embodiments, head 1004 has a concave and/or a flat distal surface and optionally a generally cylindrical shape. In some embodiments, the distal surface comprises a point (e.g., point 902 shown in Fig. 9A) at the center thereof, for example as described for dental bur 900.

Referring now to Figure 11A showing a side view of a dental kit, comprising at least one dental bur with a point and at least one dental bur with a concave distal surface, in accordance with some of the embodiments of the invention.

Referring also to Figure 11B showing a partial top view of a dental kit, comprising at least one dental bur with a point, and at least one dental bur with a concave dental surface, in accordance with some of the embodiments of the invention.

Referring also to Figures 12A-B showing schematic steps of a maxillary sinus floor elevation using a kit comprising at least one dental bur with a point, and at least one dental bur with a concave distal surface, in accordance with some of the embodiments of the invention.

In some embodiments, dental kit 1100 comprises dental burs for sinus elevation of a crestal bone with an initial height of 4 mm and less. In some embodiments, dental kit 1100 comprises dental burs having length 216 from 1-4 mm, for example with intervals of 1 mm (e.g., four dental burs with length 216 of 1,2, 3, 4 mm).

A potential advantage of using an initial dental bur that is 1 mm long and/or subsequent dental burs with intervals of 1 mm is that when penetrating the sinus membrane a projection of up to 1 mm is less likely to damage the sinus membrane.

Alternatively or additionally to 1 mm, dental kit 1100 can include dental burs with smaller intervals and/or first dental bur shorter than 1 mm for potentially increasing the control of the progress toward the sinus membrane and/or further reducing the risk of sinus membrane perforation.

In some embodiments, the diameter of the dental bur is about 3.7-4 mm, In some embodiments, the diameter of the dental burs is about 4 mm, forming an access path (e.g., access path 220) of about 4-4.2 mm, having the potential advantage of allowing relatively easy access to the membrane.

In addition, this width of the access path together with the relatively low crestal bone (height of 4 mm and less) potentially allows the clinician to view the progress of the drilling. It is noted that a low crestal bone may have experienced bone resorption and/or weakening, resulting in a flat surface that more easily allows drilling or other types of bone removal with larger diameter dental burs, such as having a 4 mm diameter.

In some embodiments, dental kit 1100 comprises at least one dental bur with a point (e.g., dental bur 900 with point 902 shown in Fig. 9A), and at least one dental bur with a concave dental surface (e.g., dental bur 200b shown in Fig. 2B). In some embodiments, dental kit 1100 is a variant of the first set of dental kit 400 shown in Fig. 4A.

In some embodiments, the shortest dental bur in the kit (for example 1 mm long), intended for the first step of drilling, comprises a point 902 on the concave distal surface thereof 210. Point 902, which comes in contact with the crestal bone, at the selected location for drilling (before starting drilling) fixates the position of the dental bur on the crestal bone. Since the surface of the crestal bone is usually characterized by some level of roughness and/or irregularity with various elevations and/or depressions, the axial protruding point can fit between the elevations and/or into the depressions and potentially fix a desired positioning on the crestal bone. Alternatively, or additionally, the point is inserted into the bone by applying sufficient axial force, for example by pressing the distal surface onto the surface of the crestal bone, before drilling. In some embodiments, using dental bur with a point 900 has the potential advantage of reducing slippage of head 204 at the beginning of drilling.

In some embodiments, if the crestal bone is relatively low, with a height of about 1 mm, the first dental bur used for drilling may penetrate the bone. A potential advantage of using a dental bur with a concave distal surface with point 902 is that a separated bone portion 1402 (shown in Figs. 14B-C) is formed (as described below). Alternatively or additionally, if the (remaining) crestal bone height is 2 mm or more, a dental bur with a flat distal surface and point 902 can be used.

In some embodiments, dental kit 1100 comprises dental bur(s) with concave distal surfaces for the last step of drilling where the crestal bone is penetrated, having a length (from the stopper to the distal surface of the bur) of about 2-4 mm depending on the specific crestal bone height of the patient. In some embodiments, the dental kit comprises dental bur(s) with concave distal surfaces having a circular symmetry, alternatively or additionally the dental kit comprises dental bur(s) with concave distal surfaces with a rim having portions that are more prominent axially than other portions thereof.

In some embodiments, penetrating the crestal bone with a dental bur having a concave distal surface forms a separated bone portion 1402 (shown in Figs. 14B-C), optionally in the shape of a bone plate and/or a bone disc. The dental bur with the concave distal surface allows leaving separated bone portion 1402 within the access path (adjacent to the sinus membrane, as shown in Fig. 14B). The remaining separated bone portion can be used to visually confirm the penetration of the crestal bone (optionally, in addition to a tactile feeling of abrupt resistance reduction). For example, after the dental bur with a concave distal surface penetrates the crestal bone, the clinician can view a central bony disc surrounded by the vascularized sinus membrane, which generally looks like a bloody buoy, as shown in Fig. 21H.

Alternatively or additionally, the penetration of the crestal bone can be confirmed when using a flat dental bur (e.g., dental bur 200) at the last step of forming the access path. The clinician can view the exposed sinus membrane, characterized by a vascular appearance compared to the crestal bone.

In some embodiments, while performing sinus membrane elevation, the osteotomes inserted after bone penetration for pushing the sinus membrane come in direct contact with separated bone portion 1402. This has the potential advantage of protecting the sinus membrane during the elevation procedure and/or reducing the risk of sinus membrane perforations by the osteotome(s).

In some embodiments, the first step of sinus elevation is performed by the last dental bur used for drilling. The dental bur having a concave distal surface pushes the sinus membrane by the rim thereof, while the separated bone portion, adjacent to the sinus, protects the rest of the sinus membrane surface.

In some embodiments, dental kit 1100 comprises a set of osteotomes, with active part lengths ranging from 1-5 mm, in intervals of 1 mm. Alternatively or additionally, the dental kit comprises an adjustable osteotome, with a dynamic active part ranging from 1-5 mm. In some embodiments, the diameter of the osteotomes is about 3.7 mm, which is smaller than the diameter of the formed access path. This potentially allows pushing separated bone portion 1402 while reducing contact with the exposed sinus membrane, having the potential advantage of further reducing the risk for sinus membrane perforation. In addition, the relatively small diameter of the osteotome (compared to the access path) has the potential advantage of easing the insertion thereof into the access path.

In some embodiments, the drilling procedure is stepped, where the dental burs are used in order of increased length (as previously described). Each dental bur has a pre-set length which defines a pre-set penetration depth into the crestal bone path. Each dental bur is inserted until the stopper thereof (which is larger in diameter than the opening of the access path) is obstructed by the crestal bone. The bone grinding in steps together with the pre-set and limited length of the dental burs allows the clinician to penetrate the bone in a controlled manner. This controlled penetration has the potential advantage of reducing the risk of excessive penetration and/or membrane perforation.

In addition, penetrating the crestal bone in steps (using several dental burs having limited penetration depth), unlike commonly used methods of penetrating with a single bar, together with forming an access path of about 4 mm wide, allows the clinician to directly view the clinical stages of the procedure. The clinician can view between steps if the bone is not yet penetrated (as shown at Fig. 2 IF), if the sinus membrane has been exposed (as shown Fig. 21H), and/or the progress of its separation. It is noted that separated bone 1402 may aid in visualizing the sinus lifting process, as the gap between the bone and the surrounding access path is expected to increase, possibly symmetrically, as the sinus membrane is lifted away from the bone.

In some embodiments, the drilling steps between the first and the last drilling steps can be performed using dental bur(s) with a concave distal surface (e.g., dental bur 200b shown in Fig. 2B) and/or a dental bur(s) with a flat distal surface (e.g., dental bur 200 shown in Fig. 2A). In some embodiments, the residues of the crestal bone while griding with a concave and/or flat distal surface changes its consistency from a solid consistency to a mushy creamy consistency, such as a foam and/or a paste, which reduces the risk of membrane penetration by bone residues.

Referring to Figure 13 showing a sinus elevation procedure using an osteotome with a gently domed flat contact surface, in accordance with exemplary embodiments of the invention.

Reffering also to Figures 14A-C showing sinus elevation through an access path with a separated bone portion using an osteotome with a gently domed flat contact surface, in accordance with exemplary embodiments of the invention.

In some embodiments, osteotome 1300 comprises a distal contact surface 1310 which is flat with a slight dome at the center thereof which defines a beveled perimeter 1311. In some embodiments, the slight dome axially protrudes contact surface 1310 by no more than 0.2 mm. In some embodiments, the diameter of the slight dome occupies between 50%-80% of the surface of the distal contact surface 1310. In some embodiments, osteotome 1300 is a variant of osteotome 402, shown in Fig. 4C. The same reference numerals have been used to denote parts that are similar to those described for osteotome 402, with the prefix 13 replacing the prefix 4.

In some embodiments, the gently domed flat contact surface 1310 potentially allows pushing the sinus membrane uniformly, while beveled perimeter 1311, which is un-sharp and/or rounded and/or smooth at the edges, reduces the risk of damaging the sinus membrane.

In some embodiments, the crestal bone was penetrated using a concave dental bur, such that separated bone portion 1402 is adjacent to the sinus membrane. The slightly domed distal contact surface 1310 mainly comes in contact with separated bone portion 1402, such that the perimeter thereof is less likely to contact the exposed sinus membrane. This has the potential advantage of reducing the risk of impairing the sinus membrane by the osteotome (e.g., as shown in Figs. 14A-C).

In some embodiments, separated bone portion 1402 has a convex shape that matches the concave shape of the concave dental bur that penetrated the bone. In some embodiments, the contact surface 1310 of osteotome 1300 is concave and matches the convex shape of separated bone portion 1402. This has the potential advantage of increasing the uniformity of forces applied on separated bone portion 1402. In some embodiments, the diameter of active part 1306 and/or contact surface 1310 of osteotome 1300 is as the diameter of separated bone portion 1402, having the potential advantage of reducing and/or preventing contact with the sinus membrane.

In some embodiments, the active part of osteotome 1310 is shaped as a cylinder. Alternatively or additionally, the wall of the cylinder comprises a waved pattern and/or a spiral pattern. These pattem(s) have the potential advantage of easing the insertion of an oversized osteotome into an access path for potentially easing compressing the bone from within the access path.

Referring now to Figure 15A-B showing an osteotome with an adjustable stopper, in accordance with exemplary embodiments of the invention.

Referring also to Figure 15C, showing an osteotome with an adjustable stopper obstructing further penetration into an access path, in accordance with exemplary embodiments of the invention.

In some embodiments, osteotome 1500 is a detailed embodiment of osteotome 1300 shown in Fig. 13. The same reference numerals have been used to denote parts that are functionally and/or structurally similar to those described for osteotome 402 and/or 1300, with the prefix 15 replacing the prefix 4 and/or 13. In some embodiments, osteotome 1500 comprises a dynamic stopper 1512 which allows to perform the sinus membrane elevation procedure in steps of ascending lengths. In some embodiments, length 1508 of active part 1506 is adjusted by using a thread 1513. In some embodiments, active part 1506 includes an inner thread, mated with thread 1513, so when stopper 1512 is rotated, it moves up and/or down along the longitudinal axis of osteotome 1500.

In some embodiments, active part 1506 comprises a plurality of markings 1514 which indicates the adjusted active length of osteotome 1500.

In some embodiments, plurality of markings 1514 is in the form of annular grooves and/or bulges that radially surround and/or partially radially surround active part 1506. In some embodiments, plurality of markings 1514 defines stepped adjustment of active length 1506, where each marking indicates on a specific active length 1508.

In some embodiments, the distance between each marking is 1 mm, which can define a stepped progression of a millimeter each step.

Osteotome 1500 is inserted into the access path and pushes the sinus membrane until stopper 1512 is obstructed, preventing further penetration (e.g., as shown in Fig. 15C), then the dynamic stopper 1512 is adjusted, optionally by being moved to the next marking, so that an additional 1 mm of active length 1516 is exposed. Then, the osteotome is re-inserted into the access path. In some embodiments, the stepped sinus elevation continues until adding 5 -6 mm to the height of the existing crestal bone (e.g., in a single-stage procedure or at one of the stages of a two- stage procedure).

In some embodiments, shaft 504 is straight. A bayonet shape may be used instead, with the potential advantage of increasing the ease and/or convenience of using osteotome 1500.

In some embodiments, the diameter of active part 1506 is about 3.7 mm for an access path with a diameter of about 4 mm and about 3.2 mm for an access path of about 2.8-3 mm.

Referring now to Figure 16A-E showing schematically stages in performing gradual filing of an access path with a bone graft, in accordance with exemplary embodiments of the invention.

Referring also to Figure 17A-D, showing an example of a gradual filing of the access path with a bone graft, in accordance with exemplary embodiments of the invention.

Figs. 16A-E and Figs. 17A-D are detailed descriptions of acts 520-532, of the flow chart shown in Figs. 5A-C, in accordance with some exemplary embodiements.

In some embodiments, at the end of the sinus elevation procedure, the sinus membrane is pushed and elevated, so that a vacant space has been formed (as shown for example in Fig. 61 or 14C ). For example, a vacant space results from pushing the sinus membrane 5-6 mm upward, which can be filled and/or grafted. In some embodiments, a bone graft, optionally Bond Apatite cement is provided by using a bone carrier such as bone carrier syringe 403, as shown in Fig. 16A. The bone graft is loaded into the opening of the bone carrier syringe 403, optionally by scraping from dish 401 (shown in Fig. 4A) which is optionally a sterile tray.

In some embodiments, bone carrier syringe 403 has a larger diameter than the diameter of the opening of the access path, for potentially preventing from bong carrier syringe 430 to entrance into the access path (as shown in Fig. 17A), by geometrically interfer to the entrance. This has the potential advantage of reducing the risk for damaging the sinus membrane by bone carrier syringe 403. In addition, the larger diameter can potentially reduce leakageof the bone graft.

In some embodiments, the outer diameter of bong carrier syringe 430 is about 4.5 mm for introducing bone graft into access path with a diameter of about 2.8-4.2 mm. For example, the diameter of bong carrier syringe 430 is 4.5-5 mm, or 4.2-4.8 mm, or about 4.5 mm, or about 5 mm, or lower or higher or intermediate ranges or diameters.

In some embodiments, the clinician selects a bone carrier syringe from a set of bone carrier syringes, having different outer diameters, optionally provided in dental kit 400. In some embodiments, this selection is based on a patient- specific access path opening dimensions, which may be defined by the diameter of the selected dental bur. For example, for an access path having an opening of 4 mm (optionally formed by drilling the crestal bone with a dental bur having a head’s diameter of 3.5-3.8 mm), a bone carrier syring of 4.5 mm can be used.

In some embodiments, separated bone portion 1402 is adjacent to the sinus membrane potentially reducing the contact of the bone graft with the sinus membrane. This has the potential advantage of reducing the risk of sinus perforation by the bone graft. In addition, the presence of the remaining separated bone portion 1402 potentially promotes bone growth after the bone graft filling.

In some embodiments, once the bone graft has been brought to the opening of access path 220, an osteotome is used to push thereof into access path 220, as shown in Fig 16B. In some embodiments, the osteotome at the first step of filling has a length shorter, optionally by 1 mm, than the last osteotome used for elevating the sinus membrane. This shorter osteotome potentially allows entering the bone graft into the access path while avoiding and/or reducing further elevation of the access path. This has the potential advantage of reducing the risk of undesired excessive sinus elevation by the bone graft.

Alternatively or additionally to elevating the sinus membrane by osteotomes prior to inserting the bone graft, the sinus membrane can be elevated while inserting the bone graft. In some embodiments, the bone graft can be used for pushing upward the sinus membrane. The bone graft can potentially apply pressure on the sinus membrane, having the potential advantage of distributing force on the sinus membrane more uniformly.

In some embodiments, the diameter of the osteotome(s) used for pushing the bone graft into the access path is larger than the diameter of the dental bur used for drilling, and larger than the diameter of the access path, but optionally still can compressed into the access path. The oversized osteotome compresses the crestal bone within the access path and, potentially improves osteo-densification. For example, the diameter of the access path in a single-stage procedure (e.g., initial crestal bone height of at least 4 mm) or in a second stage of a two-stage procedure is about 2.8-3 mm, and the diameter of the osteotome is about 3.2 mm. The osteotome radially compresses the crestal bone within the access path, resulting in increased bone density. The increased bone density has the potential advantage of enhancing the stability of the implant.

In some embodiments, the osteotome used for pushing the bone graft is of the design of osteotome 1500, having a gently domed flat contact surface, which potentially pushes the bone graft uniformly into the access path, with reduced risk of perforating the sinus membrane.

In some embodiments, the bone graft is pushed until the stopper of the osteotome is obstructed by the crestal bone, as shown in Fig 17B. This has the potential advantage of reducing un-desired further sinus membrane elevation when pushing the bone graft into the access path.

Once the osteotome penetration is obstructed, the osteotome is removed from the access path, and an additional amount of bone graft is provided to the opening of the access path, as shown in Fig. 16C. The additional bone graft amount is then pushed into the access path by an osteotome shorter from the previous osteotome, for example, shorter by 1 mm, as shown in Fig. 16D. In some embodiments, a single adjustable osteotome is used, and the length of the active part thereof is adjusted to be shortened in 1 mm.

The stepped filing of the access path with bone graft is repeated until the access path is filed with bone graft. In each step, an additional amount of bone graft is provided to the opening of the access path, and pushed into the access path by an osteotome shorter from the osteotome at the previous step, optionally, by 1 mm. alternatively or additionally to access path can be filled by a non-stepped portion, such as Dilling in one step or continuous filling.

Once the access path is filled with bone graft, as shown in Fig. 16E and Fig. 17C the access path is optionally closed.

In some embodiments, when the initial crestal bone height of the patient is above 4 mm, an implant can be deployed after the bone graft filing, immediately and/or after a few days, and then the site is being sutured. In some embodiments, when the initial crestal bone height of the patient is 4 mm or less the site is sutured and left for recovery (period of about 4-6 mm).

In some embodiments, the bone graft of choice is Bond Apatite, which serves additionally as a barrier, so that the treatment site can be sutured at the end of the filing process, as shown in Fig. 17D. Bond Apatite has the potential advantage of not necessarily needing the use of a collagen membrane as a barrier, which barrier is susceptible to infection. In other embodiments, a bond graft material other than Bond Apatite is used, and a barrier, such as a collagen membrane is is required at the end of the filling procedure, before suturing the site. Alternatively or additionally, a mixture of Bond Apatite with other bond graft(s) can be used.

Referring now to Figure 18A-B, showing exemplary components of a dental kit for performing sinus membrane elevation of a crestal bone with an initial bone height of at least 4 mm and/or for performing the second stage of a two-stage sinus elevation procedure, in accordance with exemplary embodiments of the invention.

In some embodiments, a dental kit 1800 is a variant of the second set of dental kit 400 shown in Fig. 4A. In some embodiments, dental kit 1800 is used for the second stage of the procedure which includes further elevating the sinus membrane and/or providing an implant. In some embodiments, dental kit 1800 is used for sinus lift of patients with an initial crestal bone height of 4 mm and above.

Alternatively or additionally to sinus membrane elevation procedure, dental kit 1800 can be used for creating an access path in the lower jaw, in a gradual and controlled manner, using dental burs instead of commonlu used metal drillers.

In some embodiments, dental kit 1800 comprises dental burs having lengths 216 from 4- 10 mm, for example with intervals of 1 mm (e.g., dental burs with lengths 216 of 4,5,6,7,8,9,10 mm). As previously described, lifting the sinus membrane by about 1 mm or less is less likely to injure the sinus membrane, potentially intervals of 1 mm have the potential advantage of reducing the risk for sinus membrane perforation.

In some embodiments, provided implants usually have a length difference of 1.5-2 mm, potentially intervals of 1 mm between the dental burs have the potential advantage of easing the fitting of an implant to the dimensions of the elevated bone. Alternatively or additionally, dental kit 1800 can include dental burs with different (for example smaller) intervals for potentially suiting to implants having other length differences.

In some embodiments, dental kit 1800 can include dental burs with lengths that reach up to 16-17 mm, intended for relatively long implants, such as implants of 13 mm and/or 16 mm long. In some embodiments the diameter of the dental burs’s head is about 2.8 mm, having the potential advantage of reducing the risk of bone perforation. This may be of considerable significance since the risk for bone perforation during drilling might increase at higher crestal bone heights.

In addition, dental bur’s heads with a diameter of about 2.8 mm potentially form an access path that can retain commonly used implants having a diameter of 3.2-4 mm.

Alternatively or additionally to dental bur’s heads with a diameter of about 2.8 mm, dental kit 1800 can comprise dental bur’s heads with a diameter ranging from 2.8-4 mm. In some embodiments, the diameters of the dental bur’s heads are uniform. In other embodiments, the diameters of the dental bur’s heads are varied.

In some embodiments, dental bur heads with a diameter of about 2.8 are potentially less prone to runout at the beginning of drilling, having the potential advantage of reducing slippage of the dental bur over the ridge of the crestal bone.

In some embodiments, dental kit 1800 comprises at least one dental bur with a point (e.g., dental bur 900 with pont 902 shown in Fig. 9A). In some embodiments, the shortest dental bur in the kit (for example 4 mm long), intended for the first step of drilling of the second stage comprises a point on the distal surface thereof, having the potential advantage of reducing slippage of the dental bur over the crestal bone surface.

In some embodiments, dental kit 1100 comprises dental bur(s) with concave distal surfaces for the last step of drilling where the crestal bone is penetrated, having a length of about 4-10 mm depending on the specific crestal bone height of the patient, penetrating the crestal bone with a concave dental bur can have any of the potential advantages as previously described for kit 1100. The drilling steps between the first and the last can be performed using a concave and/or a flat dental bur, as previously described for kit 1100.

In some embodiments, head 204 of the dental bur is mounted on a stopper having a cylindrical shape and diameter optionally of 6.8 mm. A stopper with a diameter of about 6.8 mm is potentially obstructed by the crestal bone when length 216 is penetrated into the bone.

Referring now to Figure 19, showing an example of a full-thickness flap at the extraction socket, in accordance with exemplary embodiments of the invention.

Referring also to Figures 20A-D, showing an example of the second stage of a two-stage procedure, in accordance with exemplary embodiments of the invention.

In some embodiments, the first stage ends with suturing the site and waiting for recovery thereof (as shown in Fig. 17D), where a healing period can take for example about 4 months. In some embodiments, after completing the first stage which increases the initial bone height under the crestal sub-sinus bone, the second stage further increases the crestal bone height and at the end thereof an implant is inserted.

In some embodiments, the crestal bone is re-exposed, optionally, by re-creating a fullthickness flap. In some embodiments, a full-thickness flap is performed as described in act 504 of the flow chart shown in Figs. 5A-C.

In some embodiments, a second access path is formed. The location for the second stage of drilling is optionally the location of the access path of the first stage. In some embodiments, when the bone graft of choice for the first stage is Bond Apatite, visible hydroxy apatite crystals can be seen on the surface, potentially easing the recognition of the designated location for drilling.

In some embodiments, the first step of drilling is performed by a dental bur having a point at the distal surface thereof (e.g., dental bur 900, shown in Fig. 9). The point (e.g., point 902 shown in Fig, 9) can be fixed on to the designated location for drilling (the location of the access path from the first stage), optionally by forcing thereof on the site having the visible hydroxyapatite crystals. This has the potential advantage of reducing the risk for slippage of the first dental bur during drilling which might result in misplacing the second access path.

In some embodiments, the first step of drilling of the second stage of the prcedure is performed using a dental bur’s head having a length 216 of 4 mm. In some embodiments, this first dental bur has a cylinder body with a concave and/or flat distal surface.

In some embodiments the first step of drilling is performed until the stopper is obstructed by the crestal bone, as shown in Fig. 20A. Then the drilling procedure in steps proceeds, where in each step a longer bur is used, as shown for example in Fig. 19A. In some embodiments, the intervals between the bur lengths are 1 mm, having the potential advantage of reducing the risk for sinus membrane perforation.

In some embodiments, the dental bur(s) having a diameter of about 2.8 mm with increasing lengths are used. In some embodiments, a dental burs with diameter of about 2.8 mm forms an access path with a diameter of no more than 2.9-3 mm. This access path is potentially suited for commonly used implants, having a width of 3-4.2 mm.

In addition, drilling with dental burs with a relatively narrow head has the potential advantage of reducing the risk of perforating of the bone while drilling. In some embodiments, if an implant wider than 4.2 is selected, the access path can be widened before inserting the implant.

In some embodiments, the drilling speed is between 400- 800 rpm, or 400-1200 rpm optionally, with external irrigation.

In some embodiments, at the end of drilling, bone penetration is confirmed using an osteotome, having an active length longer than the length of the last dental bur (e.g., length of head 204) used for drilling. For example, an osteotome longer by 1 mm from the last dental bur is inserted. If the entire length of the osteotome’s active part inserts into the access path, and/or the stopper thereof contacts the crestal bone, as shown in Fig. 20B, it is an indication that the crestal bone has been penetrated and that the osteotome is pushing the sinus membrane. For example, if the last step of drilling was performed using a dental bur having a length of about 4 mm, an osteotome with an active length of about 5 mm is introduced into the access path for confirming bone penetration. An osteotome longer by no more than about 1 mm than the last dental bur’ s head used for drilling has the potential advantage of reducing the risk of sinus membrane perforation, since a projection of about 1 mm or less, is less likely to injure the sinus membrane.

In some embodiments, if the first osteotome does not insert with the entire active length thereof into the access path, and/or the stopper thereof does not touch the crestal bone, the drilling procedure is continued, optionally, by using a dental bur having a longer head than the last used dental bur. For example, longer by 1 mm. In some embodiments, bone penetration is once again confirmed by inserting an osteotome longer than the head of the dental bur used for drilling, for example, longer by 1 mm. For example, the drilling continues with a dental bur having a head with a length of 5 mm, and the bone penetration is confirmed using an osteotome with an active length of 6 mm. The process of alternating drilling and conformation of bone penetration proceeds until an osteotome is fully inserted into the access path and/or the stopper thereof contacts the crestal bone. This technique allows the physician to control and/or oversee the bone penetration in cases of relatively high crestal bone and/or narrow access path, where a direct view of the sinus membrane is more difficult. This has the potential advantage of reducing the risk of sinus membrane perforation.

In some embodiments, the diameter of the osteotome is larger than the access path (which is usually defined by the diameter of the dental burs). This has the potential advantage of allowing improved osteo-densification. For example, an osteotome with a diameter of 3.2 mm is used for pushing the sinus membrane of the access path with a diameter of about 2.9-3 mm.

In some embodiments, the sinus membrane is elevated in steps, by increasing the length of the osteotome in each step, for example in 1 mm, as previously described in act 516 of the flow chart shown in Figs. 5A-C. In some embodiments, the stepped pushes of the sinus membrane proceeded until achieving sinus membrane elevation of about an additional 5-6 mm, for obtaining a total crestal height of about at least 10 mm.

In some embodiments, subsequently to lifting the sinus membrane, the access path is filed with a bone graft, using a bone carrier syringe and an adjustable osteotome and/or a set of osteotomes, as previously described in Figs 16A-E. In some embodiments, the width of the osteotome used for pushing the bone graft into the access path is equivalent to the width of the osteotome used for elevating the sinus membrane, optionally the same actual osteotome is used. As noted, the diameter of the osteotome is larger than the diameter of the access path.

In some embodiments, the bone graft of choice for the second stage is Bond Apatite cement which potentially has improved bone regeneration and/or potentiate osseointegration. In addition, the Bond Apatite cement is characterized by a porous structure, which absorbs blood, resulting in the softening of the cement. This property potentially makes the Bond Apatite cement less aggressive for the sinus membrane.

In some embodiments, if the crestal bone is relatively rigid, dental kit 1800 can be used in combination with a standard implant kit, which comprises metal drillers. In some embodiments, at least the first step of drilling is performed using metal drillers, which are potentially able to cut through a relatively rigid bone. Drilling with the metal drillers can be continued up to 1 mm from the sinus membrane (as evaluated using CBCT imaging). Optionally, at least the last step of drilling is performed using dental kit 1800, where the dental bur thereof comprises head 204 covered with diamond grains. The dental bur grinds the crestal bone up to bone penetration, where the flat and/or concave distal surface potentially reduces the risk for sinus membrane perforation.

Exemplary results

The following is a description and results of the application of a particular method and kit based on the above description. Not all the details are required and/or need to be applied as described. The procedure is started by evaluating the CBCT of the posterior maxilla and the height of the crest inferior to the maxillary sinus and the desired location of the placement of the implants. The procedure is initiated under local anesthesia with infiltration of 2% Lidocaine withl: 100,000 adrenaline (epinephrine) concentration. A crestal incision located slightly palatal to the ridges midline is made with two short vertical releasing incisions mesial and distally, and a minimal full thickness flap is reflected to expose the crestal bone. Once the crestal bone is exposed the osteotomy is done optionally at 600-800 RPM with maximal torque utilizing the dental burs in a sequence of lengths starting with the first dental bur, until the crestal bone is penetrated. Optionally, the RPM is raised if needed from 600 to 800 RPM in correlation with the bone density and its resistance to the drilling and the milling process. The first dental bur (e.g., having a diameter of about 4 mm and length of about 1 mm) is mounted on a contra angel surgical handpiece and utilized with sterile saline irrigation. Once the first dental bur during drilling/milling reaches to its stopper, the second dental bur (e.g., having a diameter of about 4 mm and length of about 2 mm) is used, then third dental bur (e.g., having a diameter of about 4 mm and length of about 3 mm) and the forth dental bur (e.g., having a diameter of about 4 mm and length of about 4 mm) as needed until the crestal bone is perforated and the sinus membrane is visualized. When the bone has been perforated, optionally the clinician can feel immediately that the last dental bur milling friction does not have the same resistance as when it was within the bone, the osteotomy should be stopped to avoid tearing the membrane with further advancement of the bur. During the milling process, a residue of bone in a mushy creamy consistency is formed in between the bur and the sinus membrane. In addition, due to the concave design of the bur a thin bony plate remains adhered to the sinus membrane. Potentially, the design of the dental burs and the existing limiting stoppers prevents tearing of the sinus membrane by over drilling and guaranteeing an outstanding predictable safe approach Following the osteotomy, the lifting of the sinus membrane is done gradually with the osteotomes. The length of the osteotome that is introduced can be limited by its stopper optionally from 1-7 mm according to the protocol. At this stage, we don't want to lift the sinus membrane more than 6-7 mm, as our goal is to increase the crestal height to about 4-5 mm which will be sufficient for placement of the implant and gain primary stability after bone consolidation at the second stage. Lifting more than 6-7 mm at this stage does not have any additional benefit, however it increases the risk of tearing the sinus membrane.

Lifting of the sinus membrane is initiated by restricting the osteotomes length optionally to one millimeter more from the final dental bur length that was used at the time of creation of the osteotomy when the bone was perforated, For example, if the last dental bur length was 3 mm, the osteotome length in its first introduction should be 4 mm, and gradually adding one millimeter each time the osteotome is re- introduced to lift the sinus membrane to optionally 6 or 7 mm, but no higher. As mentioned earlier, lifting more than 7 mm is not necessary and can jeopardize the procedure by tearing the membrane.

After lifting the membrane with the osteotomes, the augmentation of the sinus cavity is optionally accomplished with “Bond Apatite®” bone cement. A bone graft cement like Bond Apatite®” is the material of choice due to its viscosity and cementing abilities as well its true regeneration properties. The material is activated within its syringe and ejected into a sterile dish, immediately after a piece of dry gauze is placed above the material and with finger pressure over the gauze for 1-2 seconds the material is pressed to remove residual moisture. The gauze is removed, and the material is ready to be reloaded into the bone carrier syringe.

Following loading into the bone carrier, the syringe is introduced into the osteotomy and extruded into the elevated sinus area. Optionally an osteotome with the same final length of the osteotome that was used during the lift of the membrane is then utilized to push the graft material into the elevated sinus area. The bone carrier is loaded again, and the graft is introduced into the osteotomy now the length of the osteotome is reduced by one millimeter from its last introduction, then another layer of Bond Apatite® is injected into the osteotomy and the length of the osteotome is reduced again optionally by 1 mm and so on, each time filling the osteotomy with the graft, another millimeter is reduced until the osteotome length has reached 1 mm and the osteotomy is almost filled completely with the graft material. At this stage, a final amount of graft is placed to cover the osteotomy and is compacted with dry sterile gauze and finger pressure optionally for 3 seconds. The flap is then closed, optionally with PGA 4.0 resorbable sutures or a non-resorbable suture depending on the practitioner's preference. However, chromic gut or gut sutures are not recommended as they might resorb too fast. Soft tissue closure is done without a membrane due to the barrier effect of this type of graft material, After suturing an intraoral wound dressing “Augmashield” (Augma Biomaterials) was placed on top of the sutured area to enhance initial soft tissue healing. A post-op radiograph is taken and post operative instructions are given to the patient with an analgesics prescription. While pushing the material into the sinus due to its viscosity and cementing properties the material is dispersed uniformly within the sinus cavity and in this way the sinus can be augmented safely without disbursement through the sinus as may happen with particulate type graft materials. The site is left to heal and allow bone consolidation for 4-5 months. During that time period, we expect a vertical resorption of about 2 mm from the height that we lifted at the first procedure. Following that healing period re-evaluation is performed using a CBCT to determine that sufficient bone height at the crestal level has been achieved. When this is confirmed the second phase of the “Summers technique” can be performed for further augmentation of the sinus and simultaneous implant placement.

The results of the treatments are presented in the following table:

In conclusion, the method(s) and dental instrument(s) previously described in this document allows a minimal technique sensitive approach for bone regeneration and vertical sub-sinus bone augmentation so it can be done safely and predictably for most of the clinicians less dependent of their experience and surgical skill without suffering the complications inherent in a lateral sinus approach. Thus, allowing creation of a stable base to permit subsequent implant initial stability at placement after the initial augmentation has healed and immature bone is present at the 2nd surgery when the implant will be placed. Bond Apatite has been documented to convert to host bone over a 4 — 6-month period dependent on the volume of graft that had been placed and is well tolerated by host tissues, making it an ideal material for sinus augmentation. The materials hard setting prevents disbursement in the sinus during initial healing and eliminates loss of height during the healing that occurs with particulate graft materials when an implant is not present to tent the sinus membrane. Additionally the elimination of the need for a membrane reduces treatment costs for the patient as well as simplifies the surgical procedure for the practitioner.

It is expected that during the life of a patent maturing from this application many relevant bone drilling technologies will be developed; the scope of the term bone bur is intended to include all such new technologies a priori.

As used herein with reference to quantity or value, the term “about” means “within ± 10 % of’.

The terms “comprises”, “comprising”, “includes”, “including”, “has”, “having” and their conjugates mean “including but not limited to”.

The term “consisting of’ means “including and limited to”.

The term “consisting essentially of’ means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure. As used herein, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof

Throughout this application, embodiments of this invention may be presented with reference to a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as “from 1 to 6” should be considered to have specifically disclosed subranges such as “from 1 to 3”, “from 1 to 4”, “from 1 to 5”, “from 2 to 4”, “from 2 to 6”, “from 3 to 6”, etc.; as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

Whenever a numerical range is indicated herein (for example “10-15”, “10 to 15”, or any pair of numbers linked by these another such range indication), it is meant to include any number (fractional or integral) within the indicated range limits, including the range limits, unless the context clearly dictates otherwise. The phrases “range/ranging/ranges between” a first indicate number and a second indicate number and “range/ranging/ranges from” a first indicate number “to”, “up to”, “until” or “through” (or another such range-indicating term) a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numbers therebetween.

Unless otherwise indicated, numbers used herein and any number ranges based thereon are approximations within the accuracy of reasonable measurement and rounding errors as understood by persons skilled in the art

As used herein the term “method” refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts.

As used herein, the term “treating” includes abrogating, substantially inhibiting, slowing or reversing the progression of a condition, substantially ameliorating clinical or aesthetical symptoms of a condition or substantially preventing the appearance of clinical or aesthetical symptoms of a condition.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. It is the intent of the applicant(s) that all publications, patents and patent applications referred to in this specification are to be incorporated in their entirety by reference into the specification, as if each individual publication, patent or patent application was specifically and individually noted when referenced that it is to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is/are hereby incorporated herein by reference in its/their entirety.

Claims

WHAT IS CLAIMED IS:

1. A method of sinus lifting, comprising:

(a) selecting a patient with a potential implant location in an upper jaw adjacent a sinus and having a crestal height of 4 mm or less at said location;

(b) forming a crestal access path to said sinus;

(c) lifting a sinus membrane of said sinus via said access path; and

(d) implanting a support in said sinus under said sinus membrane.

2. The method according to claim 1, wherein said method does not include forming a lateral access path to said sinus.

3. The method according to any of the preceding claims, wherein said forming a crestal path comprises forming by drilling in stages, each stage using a bone removal device with a stopper, the stoppers defining increasing stopping distances.

4. The method according to any of the preceding claims, wherein said forming comprises detecting when the path reaches the sinus by tactile feel of an abrupt change in crestal resistance.

5. The method according to any of the preceding claims, wherein said forming comprises drilling using a non-sharp bone removal device.

6. The method according to claim 5, wherein said non-sharp bone removal device has a flat front surface extending at least 70% of a cross-sectional area of said bone removal device detecting, measured in a transverse plane to the crestal direction which is an axial direction of the bone removal device.

7. The method according to claim 6, wherein said non-sharp bone removal device has a shape of a truncated cone.

8. The method according to claim 5, wherein said non-sharp bone removal device has a concave front surface extending at least 70% of a cross-sectional area of said non-sharp bone removal device, measured in a transverse plane to the crestal direction which is an axial direction of the non-sharp bone removal device.

9. The method according to any of claims 5-8, wherein said forming a crestal access path comprises penetrating the crestal bone with a non-sharp bone removal device having a concave front surface.

10. The method according to claim 9, wherein said penetrating the crestal bone comprises terminating said forming of said crestal access path when a separated portion of said crestal bone is formed.

11. The method according to claim 10, comprises confirming penetration into said crestal bone by viewing said sinus membrane around said separated portion of said crestal bone.

12. A method of sinus lifting, comprising:

(a) selecting a patient with a potential implant location in a jaw;

(b) forming a crestal access path, using at least one bone removal device with a flat or concave distal surface.

13. The method according to claim 12 wherein said forming a crestal access path comprises forming a crestal access point using at least one bone removal device with a concave sinus membrane.

14. A dental bur for sinus lifting, comprising: an elongate shaft with a proximal end configured for attaching to a dental drill bit- socket; a dental bone bur head with a diameter of 4 mm or less and a front surface; and a stopper with a stopping surface positioned 1 mm or less from said front surface of said bur head, wherein said front surface defines a drilling diameter of at least 2 mm and an axial extent of less than 0.5 mm.

15. The dental bur according to claim 14, wherein said head is shaped as a cylinder.

16. The dental bur according to any of claims 14-15, wherein said head has a diameter of 2.8-4 mm.

17. The dental bur according to claim 14, wherein said front surface comprises a nonsharp of a non-pointy surface.

18. The dental bur according to claim 17, wherein said non- sharp bur has a shape of a truncated cone.

19. The dental bur according to claim 17, wherein said front surface is flat.

20. The dental bur according to claim 17, wherein said non-sharp dental bur has a flat front surface extending at least 70% of a cross-sectional area of said dental bur, measured in a transverse plane to the crestal direction which is an axial direction of the dental bur.

21. The dental bur according to claim 17, wherein said front surface is concave.

22. The dental bur according to claim 17, wherein said non-sharp bur has a concave front surface extending at least 70% of a cross-sectional area of said bur detecting, measured in a transverse plane to the crestal direction which is an axial direction of the bur.

23. The dental bur according to any of claims 14-22, wherein a forward facing rim of said bur has a rounded edge facing forward.

24. The dental bur according to any of claims 14-23, wherein said front surface drilling diameter is at least 60% of a maximal diameter of said head.

25. The dental bur according to claim 17 wherein said front surface is non-pointy except for a point at the center thereof, wherein said head defines an axis of rotation and wherein said point is located along said axis of rotation.

26. The dental bur according to claim 25, wherein said point protrudes axially no more than 0.5 mm, from said flat front surface or from said forward facing rim of said concave front surface.

27. The dental bur according to any of claims 14-26, wherein said stopper is integral and fixed in location relative to said elongate shaft and said head.

28. The dental bur according to any of claims 14-26, wherein said stopper is movable relative to said front surface.

29. A dental bur kit comprising a bur according to any of claims 14-28, in combination with additional burs with different stopping distances, in steps of less than 1.1 mm.

30. A dental bur kit for sinus lifting comprising: a plurality of bone burs with a drilling diameter of less than 4 mm, each bur comprising: a head having a front bone removal surface; and a stopper having a stopping surface distanced a stopping distance from said head, wherein each bur has a different stopping distance, the starting distances starting from 1.1 mm or less and increasing in steps of less than 1.1 mm until at least 4 mm.

31. The kit according to claim 30, wherein said front bone removal surface is flat or concave over at least 60% of its area.

32. The kit according to claim 31, wherein said plurality of bone burs comprises at least one dental bur, wherein the front bone removal surface thereof comprises a point at the rotation center, configured to be used at a first stage of forming a crestal access path.

33. The kit according to any of claims 31 or 32, wherein said plurality of bone burs comprises at least one dental bur comprising a concave front bone removal surface and configured to be used at a last stage of forming a crestal access path.

34. The kit according to claim 30 or claim 31, comprising an additional plurality of bone burs with a stopping distance of above 5 mm.

35. The kit according to claim 34, wherein a drilling diameter of said additional plurality of bone burs is different from a drilling diameter of said plurality of bone burs.

36. The kit according to any of claims 30-35, comprising a plurality of osteotomes, each having a stopper, each stopper set at a different stopping distance and at least one suitable for reaching 5 mm or less.

37. The kit according to any of claims 30-36, comprises an adjustable osteotome, having a movable stopper along the longitudinal length thereof, wherein moving the stopper modified a length of an active part of the osteotome.

38. The kit according to claim 37, wherein the adjustable osteotome comprises markings for indicating the length of the active part.

39. The kit according to any of claims 36-38 wherein the osteotome comprises a flat distal contact surface with a gentle dome at a center thereof, wherein said dome axially protrudes from said distal surface by no more than 0.35 mm, and wherein a surface of said dome occupies no less than 50% of said distal surface.

40. The kit according to claim 39, wherein said contact surface of said osteotome comprises a smooth rim.

41. The kit according to any of claims 30-36, comprising a bone filler injector and bone filler material.

42. The kit according to claim 41 , wherein an outer diameter of said bone filler injector, is larger than an opening of said crestal access path.

43. A dental bur kit for sinus lifting comprising: a plurality of bone burs wherein, each dental bur comprises: a head having a front bone removal surface; and a stopper having a stopping surface distanced a stopping distance from said head, wherein each bur has a different stopping distance, the starting distances starting from 4.1 mm or less and increasing in steps of less than 1.1 mm until at least 10 mm.

44. The kit according to claim 43, wherein each bone bur of said plurality of bone burs has a drilling diameter of less than 5 mm.

45. The kit according to any of claims 43-44, wherein said front bone removal surface is flat or concave over at least 60% of its area.

46. An osteotome, for lifting a sinus membrane during maxillary sinus lift procedure, comprising: an elongated body; a cylindrical active part mounted on said elongated body at one end thereof; and a contact surface at a second end there, wherein the contact surface comprises a flattened dome, having a height of no more than 0.35 relative to said contact surface and occupies no less than 50% from said contact surface.

47. The osteotome of claim 46, wherein said contact surface comprises a smooth rim.

48. The osteotome of any of claims 46-47, wherein said elongated body comprises a stopper, and wherein said active part is mounted on said body.

49. The osteotome of any of claims 46-48, wherein said osteotome is an adjustable osteotome, having a movable stopper along the longitudinal length thereof, wherein moving the stopper modified a length of the active part of the osteotome.

50. The osteotome of any of claims 46-49, wherein the adjustable osteotome comprises markings for indicating the length of the active part, wherein intervals between the markings are 1 mm.