Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
  • A61C5/00—Filling or capping teeth
  • A61C5/40—Implements for surgical treatment of the roots or nerves of the teeth; Nerve needles; Methods or instruments for medication of the roots
  • A61C5/42—Files for root canals; Handgrips or guiding means therefor

Definitions

• Endodontic instruments more specifically: an instrument wherein the head and shaft are separately manufactured and then joined; wherein an instrument may have a shaft with a first composition and a head located at a removed end of the shaft, the head with a second composition; and an instrument with an integral retrieval means.
• Endodontic instruments are used to clean and shape a root canal, for subsequent filling.
• Prior art endodontic instruments are typically made from the same material and in a single step as an integral unit with an elongated working member having a cutting portion for cutting the canal and a non-cutting portion for insertion into a handle.
• a handle which is attached to the first or near end of the shaft is rotated while the instrument is inserted into the canal where the rotation of the cutting head or cutting portion against the walls of the tooth canal effects a reaming or cleaning of the canal .
• Applicant provides a number of improvements in prior art endodontic instruments and irrigating devices.
• 1 Applicant provides an endodontic instrument with a working portion created by the joiner of a separate shaft (non-cutting portion) and a separate head (cutting portion) . This is provided in place of the prior art teaching of a unitary working member with a cutting portion at one end thereof.
• Applicant's endodontic instrument provides for a number of advantages over the prior art as set forth more fully below.
• Further Applicant provides an endodontic instrument including means for retaining a shaft on the instrument if the shaft were to break. Further, Applicant provides an endodontic instrument with a friction grip handle for engagement with a drive tool.
• the purpose of the shaft is to locate the head of the instrument into the canal and bring it back. Further, the shaft is used to drive the head. In the past, materials of the one piece head and shaft were the same (typically metal) so you could not optimize head and shaft requirements. While the shaft should be flexible to keep the head centered in the canal and be capable of bringing the head into and out of the canal, the head of the shaft should be an effective cutting agent shaped and made of a material that will promptly and effectively cut the canal walls. Applicant provides for an endodontic instrument in which a shaft and head are manufactured separately, then joined together, with typically, a handle attached to the shaft on the end opposite the head. The shaft and the head may be manufactured from the same material or from different material.
• the shaft and head were an integral member made of the same composition; that is, stainless steel, nickel titanium, etc.
• Applicant also provides a novel device with two or more different materials; a shaft of a first composition (optimally flexible and durable) and the head of a second composition (optimally hard and shaped with cutting edges) for effectively cutting tooth canal material.
• the function of the head is to cut, clean, and stay centered in the canal and remove the abraded material. This is best performed by materials whose properties are different than the function of the shaft, which should be flexible, durable, and capable of placing a head into and out of a root canal . Breakage of an instrument in a canal creates obvious problems.
• Rotary endodontic instruments typically rotate rapidly and flex while the dentist is shaping and cleaning within the root canal. The repeated flexing causes them to, ultimately, fail by breaking, usually along the shaft between the handle and the head of the instrument. If the breakage occurs during use, the dentist is faced with the often daunting task of recovering the broken pieces or leaving the broken pieces in the tooth .
• Applicant provides a solution to the breakage problem by focusing on the retrieval of the broken pieces of the instrument.
• Applicant's endodontic instrument may be made or constructed with a shaft of stainless steel, nickel-titanium or any other suitable material. The breakage of a shaft becomes less of a concern to the dental professional when structural means are provided that will provide a retrieval mechanism. When breakage of the instrument occurs inside the tooth the broken pieces of the instrument should be removed.
• An i invention which has a built-in retrieval device clearly has
• Applicant also provides yet another unique endodontic 7 instrument for cleaning a tooth canal and a method for s manufacturing the same.
• This instrument includes a separate 9 shaft to which a separate head is joined.
• Applicant's novelty 0 lies in providing for manufacturing the shaft separate and i apart from the head and, following the manufacturing the head 2 and shaft separately then joining the two. This provides for 3 advantages including optimizing the performance of the two individual components. It is noted in this embodiment of this
• the shaft and head material are of the same composition or s wherein the shaft and head material are different ⁇ compositions.
• 8 may be made from stainless steel, nickel titanium, plastic or
• the shaft is manufactured and fashioned as an o elongated typically cylindrical, hollow tube or solid wire, i coil wound section, or a series of gears, or wire mesh with 2 the head manufactured separately in a manner and shaped for 3 efficient cutting and cleaning.
• the pieces are then joined 4 as by bonding, welding, gluing, etc. (method of joining) .
• a shaft may be made as set forth above 6 and a head may be provided of a different material as such as 7 those materials set forth above and then the shaft and the s head joined.
• Applicant's provide for this and other objects by s providing a rotatable endodontic instrument having a handle ⁇ for attachment to a shaft, the shaft with a near end and a removed end, the handle at the near end thereof and a head, cooperating with the shaft at the removed end of shaft so as
• Applicant further provides for a sleeve, dimensioned for receipt over the shaft, to substantially i enclose the shaft between the handle and the head of the 2 shaft, with the sleeve and the shaft being glued, soldered or otherwise attached to one another. Therefore, if breakage of 4 the shaft occurs the sleeve still maintains its integrity and will substantially enclose the broken piece, typically preventing it from escape from the instrument and remaining in the canal. Applicant further provides for this and other objects and purposes in providing an endodontic instrument which includes a shaft, the shaft enclosed by a coil spring and attached to i the coil spring such that both the shaft and the coil spring rotate together. At one end of the shaft is a head and at the 3 other end of the shaft is a handle. Rapid rotation by the handle allows the head to do its cutting work on the tooth. However, should the shaft break the coil spring will retain, within the coil, the broken piece.
• Fig. 1 is a side elevational view of the three piece endodontic instrument having a handle, shaft and head, the shaft being made of coiled metal wire.
• Fig. 1A is a side elevational view of the endodontic instrument of Fig. 1 but with a handle adopted to accept a friction grip mechanism.
• Fig. 2 is a partial side elevational view of the Fig . 1 is a side elevational view of the three piece endodontic instrument having a handle, shaft and head, the shaft being made of coil metal wire.
• Fig. 1 is a side elevational view of the three piece endodontic instrument having a handle, shaft and head, the shaft being made of coil metal wire.
• FIG. 3 is a partial side elevational view of the endodontic instrument showing a tubular shaft for receipt of a separate head thereinto, the head having ridges as cutting elements instead of grooves.
• Figs. 4 and 5 are side elevational, partially cutaway views of a removed end of an alternate preferred embodiment of Applicant's endodontic instrument.
• Fig. 6 and 6A are a side elevational view of Applicant's
• Fig. 7 is a side elevational view (cut away) of
• s Fig. 8 is a cross sectional view perpendicular to the
• Fig. 9 is a partial view of Applicant's endodontic
• FIG. 10 A, B, and C illustrate yet another alternate 2 preferred embodiment of Applicant's present invention.
• 3 Fig. 11 illustrates yet another alternate preferred 4 embodiment of Applicant's present invention, here featuring a s mesh sleeve.
• 6 Fig. 12A and 12B illustrate cutaway and side elevational 7 views of yet another alternate preferred embodiment of s Applicant ' s present invention featuring a shaft contained 9 within round wire strands.
• 0 Fig. 13 illustrates a side elevation view of another i embodiment of Applicants' endodontic instrument with a coiled 2 spring as a shaft.
• 1 Fig. 14 illustrates an exploded elevational view of yet
• Fig. 15 illustrates an exploded side elevational view of
• Fig. 16 illustrates an exploded side elevational view of
• Figs. 1, 1A, 2 and 3 represent an endodontic 10 i instrument comprised of three parts: a head 12 attached to the 2 removed end of a shaft 14, the near end of the shaft having a 3 handle 16.
• the handle may have a latch indent 18 4 for attachment of the handle to a dental hand piece.
• the two handles in Figs. 1 and 1A differ in that in Fig. 6 1 there is a latch indent 18 in the handle, and in Fig. 1A, 7 handle 161 has a narrower diameter and is designed to be s accepted in a friction grip mechanism of a drilling device, 9 such as those manufactured by NSK.
• Applicants novel friction o grip handle is smaller in diameter (typically less than about ⁇ 4mm and preferably about 1.6mm and shorter in length typically
• IO 1 in Fig. 1 Any other type of suitable handle may be used.
• the handle may be made out of aluminum, brass, plastic,
• the cutting head 12 may be of any hard, durable material
• Heads may be ground by a machinist using a five axis grinding machine such as one
• the shaft 14 may be made of any IO flexible, durable material, such as metal (for example li stainless steel or nickel-titanium) , plastic, rubber, carbon
• the shaft may be any material, composites, or the like. Further, the shaft may be any material.
• Figs. 10B, 11, 13 and 14 for illustrations of variations is of Applicants drive shafts, including gear (Fig. 10B) , wire i9 mesh (Fig. 11), tightly wound wire coils (Fig. 13 and 14).
• 2o Depth gauge 30 may be 2i provided along the shaft or handle to allow the dentist a >2 means of determining the depth of the instrument in the canal.
• the shape of the head 12 is noted to have a rounded or pointed nose 12A, which is helpful to accomplish the centering purposes of the instrument. However, the shape of the head may be any suitable shape.
• the surface of the head is seen to contain cutting edges, here either grooves 20 or Applicant's novel ridges 22.
• Grooves or ridges may take a spiral shape with a longitudinal axis of the instrument which allows for both effective cutting and shunting of the cut debris towards the canal's orifice (towards the handle) . Both the grooves and the ridges typically have edges 12B which will cut into the canal wall when the head is urged into the tooth.
• the ridges may be formed from diamonds layered over the body of the head, bonded to the head by electromechanical galvanic gluing or other ways known in the trade.
• the head is made of a hard material, meaning a material that will cut dentin within the tooth, and may itself be composed of one or more materials, such as metal (for example, stainless steel and nickel titanium) , ceramic, diamond, or other mineral, rubber, composites, carbon fiber, or anything else that is hard.
• the shaft should be flexible and durable and is not required to have all of the same properties of the head.
• the cutting portion has grooves or ridges with cutting edges thereon, and may be spiraled such that it may cut dentin (being harder than the tooth material) and, with the spiral shape, may transmit the cut debris along the longitudinal axis of the instrument away from the head.
• the rotating cutting member has a longitudinal axis and, further, a longitudinal bore 106A and rides on a retainer wire 104.
• a stop member 106 here cone-shaped (or may be circular or rounded or any other suitable shape) , where the base of the cone has a diameter greater than the uniform diameter of the retainer wire 104.
• the retainer wire is
• Applicant's endodontic instrument 10 2 includes a shaft 14 having a removed end 14A, a body 14B and 3 a near end 14C.
• the shaft is typically cylindrical and 4 typically dimensioned between .001 millimeter and 2.0 millimeters in thickness and is typically 1.0 millimeter to 100 millimeters in length.
• the shaft may be made from nickel- titanium, stainless steel, plastic or any other suitable material .
• a handle 16 At the near end 14C of Applicant's shaft 14 and joined thereto is a handle 16, which may either be for engagement i with a friction grip or a latch handle for engagement with a 2 motor drive.
• the handle is typically cylindrical and made of 3 aluminum, brass, plastic, or any other suitable material.
• a head 12 At the removed end 14A of Applicant's shaft is a head 12, the head having cutting blades or cutting means 12A thereon and, optionally, having a cutting or non-cutting pilot portion 12B thereon.
• the head may be formed from the same material as the shaft or from a different material such as: stainless steel, nickel titanium, carbide steel or any other suitable material.
• Fig. 6 shows the use of depth gauges or rings 30 along the shaft whereas Fig. 6A shows them along a narrow section of the handle. In Fig.
• the sleeve may be a coil spring, tightly coiled with little or no space between the adjacent throws of the coil, and typically made of stainless steel or other suitable biocompatible material.
• the sleeve typically being a coil spring, may bend or flex and is attached to the shaft near the head or to the head itself so as to rotate therewith. Attachment by mechanical or adhesive means 220 such as by welding, gluing or soldering may be made, typically near the point near where the head joins the sleeve.
• the purpose of the coil spring sleeve is to allow the shaft to flex but if the shaft breaks, to contain within the 1 coils of the coil spring the broken pieces. This allows the
• Fig. 7 shows use of a solid shaft 14
• Fig. 6 shows a i hollow tube shaft 14
• both may be covered by the coil spring sleeve.
• Fig. 7 shows the head integral with the shaft but they may be two separate parts (as in Fig. 6, 220 being an adhesive or weld) .
• Fig. 8 is a cross section through the body of the endodontic instrument of Fig. 7 showing the sleeve over a solid shaft.
• Fig. 9 shows the coil spring sleeve with adhesive 220 holding the head to the shaft and sleeve to the shaft near the head.
• the sleeve is typically attached to the shaft only near the head and further, because in this embodiment the sleeve is not attached to the rotating handle (which turns the shaft), when the shaft, breaks the head and the sleeve portion proximal to the break will stop rotating and the dentist can slide the proximal (still spinning) shaft from the sleeve and retrieves the sleeve and broken section of the shaft and the head by grasping the sleeve at its proximal end with an appropriate tool.
• Fig. 10A-C illustrates an additional embodiment of the retainer wire here, a centrally located retainer wire 224 where the retainer wire may be stationary (or may rotate) with a boss 225 on the distal end holding the cutting head 227 in place.
• a shaft 226 (Fig. 10B) is shown made up of a series of similarly shaped, discrete gears 228, strung along the retainer wire and held between the boss and the proximal end of the retainer wire.
• Use of the multiplicity of separate gears with interlocking teeth 230 should prevent the shaft from breaking apart as the gears will likely "strip" before breaking since they are driving the head but will not fall off due to the retainer wire. Further, use of this design will allow the shaft to easily flex without “stretching" the metal.
• Fig. 11 illustrates a wire mesh sleeve 218A made from fine wires woven together. This sleeve may be used in place of sleeve 218 in the embodiments illustrated in Figs. 6 through 9.
• Fig. 12A and 12B illustrate use of a solid shaft 14 with
• Fig. 14 illustrates yet another embodiment of O Applicant's endodontic instrument 10.
• a i coil wound shaft 14 is used, and attached to the handle and to 2 a cutting head 216.
• This embodiment uses a retainer wire 104 3 and a coil wound drive shaft for driving a cutting head 216. 4
• the retainer wire is enclosed within shaft 14.
• Shaft 14 s is not attached to the retainer wire.
• Shaft 14 is attached to 6 the handle and the cutting head and causes the cutting head to 7 rotate. As in earlier embodiments, any breakage of the shaft s 14 will be retained on retainer wire 104.
• Using a multi-filar 9 shaft provides an instrument with a longer life than current 0 instruments provided.
• FIG. 15 illustrates an endodontic instrument 10 which 2 instrument has a unitary shaft/cutting head member 217.
• a spacer 219 may be used where the near end of unitary cutting head shaft 217 inserts into handle 16 to fit the handle to the shaft.
• This one piece design may be used with sleeve 218 which may be made of single or a multi-filar coil winding from stainless steel, MP35N, platinum content and many other alloys.
• sleeve 218 which may be made of single or a multi-filar coil winding from stainless steel, MP35N, platinum content and many other alloys.
• the sleeve is bonded, welded or otherwise attached to the shaft and head of member 217.
• Star Guide Corporation provides such sleeves in appropriate dimensions.
• Fig. 16 illustrates the use of a tubular shaft 14 with head 12 inserted into the removed end.
• the tube may be nickel-titanium, stainless, plastic steel, fiberglass or any other suitable material.
• the sleeve will slide over the shaft and will be attached to the shaft near the cutting head (the cutting head being inserted here into the tubular shaft at the removed end) . Welding, gluing or otherwise retaining the retrieving sleeve 218 to the shaft and only near the head of the shaft (at "A") any breakage in the shaft between the point of attachment and the handle will cause the sleeve to stop spinning. One can then remove the head and the sleeve from the tooth canal.
• Applicant provides an endodontic instrument whereby the working portion (shaft and cutting head) of the instrument is made from two or more parts rather than a single piece.
• the component parts may be made of the same material or of different materials.
• the cutting head portion may be attached to a shaft by means of gluing, welding, soldering or any other reliable means of attaching the two or more parts.
• Each of the component parts may also be made from one or more parts of the same or different materials.
• the cutting head component may be made from one or more parts, solid or hollow from the same or different material.
• the cutting head may have flutes cut into it.
• the cutting head may also have ridges (such as diamonds) layered over its surface.
• the cutting head may have a hole through a portion of or through its entire length for insertion of a shaft or retainer wire.
• the noncutting shaft may also be made of one or more parts, solid or hollow from the same or different materials.
• the noncutting shaft may be made of one part of solid wire, wire mesh, hollow tube, coil, or multi-filar cable.
• the noncutting shaft may be made of two or more parts such as: a series of gears; an outer part of wire mesh, hollow tube, coil, multi-filar cable and an inner part of solid wire, coil or tube.
• Applicant also provides an endodontic instrument whereby the shaft has attached a novel friction grip handle. 1 Applicant also provides an endodontic instrument whereby
• Applicants instrument provides that when one or more components fail, all the components, including the failed s piece, can be retrieved.
• Applicant provides an instrument ⁇ whereby components, including the failed piece, can be retrieved; and whereby components are specifically designed
• the retrieval 3 mechanism may consist of a retrieval wire with a boss on the 4 end that is threaded through the shaft and cutting head.
• the s retrieval wire may be stationary or rotate.
• 6 Applicants provide an instrument with an early warning 7 mechanism whereby one or more components are designed to fail s before another. When the inner or outer portion breaks, it 9 warns the dentist that the instrument should no longer be 0 used.
• An early warning mechanism may consist of an outer i sleeve and an inner core wire.
• the inner core wire is made of 2 a design such as solid wire and material such as stainless 3 steel that is designed to break before the outer sleeve.
• the i outer sleeve is made of a design and material such as wire

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• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Neurology (AREA)
• Neurosurgery (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Surgery (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Dentistry (AREA)
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• Life Sciences & Earth Sciences (AREA)
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• Dental Tools And Instruments Or Auxiliary Dental Instruments (AREA)

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• 1999
  • 1999-12-07 US US09/455,729 patent/US6579092B1/en not_active Expired - Lifetime
• 2000
  • 2000-08-07 DE DE10084879T patent/DE10084879T1/de not_active Withdrawn
  • 2000-08-07 GB GB0202079A patent/GB2369576A/en not_active Withdrawn
  • 2000-08-07 WO PCT/US2000/021471 patent/WO2001010330A1/en not_active Ceased
  • 2000-08-07 JP JP2001514859A patent/JP2003517350A/ja active Pending

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