WO2008120877A1

WO2008120877A1 - Dental implant apparatus

Info

Publication number: WO2008120877A1
Application number: PCT/KR2008/001507
Authority: WO
Inventors: Sang Jik Lee
Original assignee: Sang Jik Lee
Priority date: 2007-03-30
Filing date: 2008-03-18
Publication date: 2008-10-09
Also published as: KR100841218B1

Abstract

In this invention, macrothreaded portion of fixture wherein meets with cancellous bone have conical shape with about 3~10°angle of inclination(ϑ). If operator turns the fixture by force, it can be screwed into patient's jawbone due to 2-4 grooves, long and short grooves, and cutting edges formed on the macrothread portion of fixture. So operator can save time for implantation and increase initial stability of fixture. Also the conventional complicated implant impression procedure becomes simple without removing the healing abutment from fixture and repositioning it after impression making through several improvements of healing abutment and impression coping.

Description

DENTAL IMPLANT APPARATUS

Technical Field

[I] Provided are, firstly, a dental implant fixture which can minimize drilling and tapping procedures through it's self drilling and self tapping efficiency even in a very dense bone. Secondarily, healing abutment and impression coping which has snap fastener structure for easy and convenient impression making procedure. Background Art

[2] When teeth, used for digestion of food, are lost for some reason, people can have difficulties in chewing and digestion. So teeth were to be considered one of the most important part of body and plays important role to maintain healthy life. [3] Lost teeth should be substituted by prosthetic work because human teeth do not have successor once they are lost after permanent dentition. [4] But conventional dental prosthetic work need some kind of damage to neighboring dentition and/or gum structure. Also removable dental prostheses have disadvantage of decreased biting force, uncomfortableness and foreign body sensation. [5] Several studies about dental implant treatment were done to solve these problem caused by conventional dental prosthetic work not to damage natural teeth and supporting structure.

[6] Recently, extensive studies are being made on the dental implant

[7] technology as a prosthesis means for the treatment of dental fall off and

[8] damages. The purpose of this technology is to embed a dental implant having

[9] the functions equal to those of the original tooth in the position from which

[10] the tooth is fallen off or extracted because of the damage.

[I I] The implant comprises an implant body (fixture ) made of titanium

[12] which is embedded in jawbone, a gingiva-penetrating member which is engaged

[13] with an upper end portion of the implant body, a post core made of either

[14] titanium or gold which is screwed through the gingiva-penetrating member into

[15] a post core fixing hole provided in the implant body, an artificial tooth

[16] fixed on the post core using a securing pin or cement. Such a dental implant

[17] allows direct transmission of the occlusal force to jaw bone like natural

[18] tooth does.

[19] The method for the dental implant treatment comprise surgical and

[20] prosthetic procedures. In general, surgeon open flap to expose underlying

[21] bone structure for implantation and then suture back exposed area to allow

[22] the implant to be osseointegrated in the bone. [23] Most of conventional dental implants usually have cylindrical or root

[24] form shape which has round apical end and the shape and depth of their

[25] cutting edge are milled uniformly from upper portion of implant to apex. So

[26] they do not have enough self tapping ability and surgeon has to enlarge

[27] alveolar bone sufficiently with lots of drilling device. These process is

[28] very complicated and sometimes surgeon cannot get good initial stability.

[29] After an implant has been implanted into jaw bone of a patient, it is

[30] typical to allow the impalnt to settle in the bone and to allow the bone to

[31] grow around the implant over a period of, for example, three to six months.

[32] Subsequently, restorative dentist can make impression in case fixture is non-

[33] submergible type but surgeon has to remove soft gum tissue to expose buried

[34] implants in case they are submergible type.

[35] In case of submergible type, surgeon change cover screw to healing

[36] abutment and wait until gum heals. And then restorative dentist remove cover

[37] screw or healing abutment to connect impression coping to make impression for

[38] the artificial teeth on top of implants. Sometimes restorative dentist has to

[39] take x-ray to verify whether impression coping is correctly connected. These

[40] procedure is very time consuming and make dentist exhausted.

[41]

Disclosure of Invention

Technical Problem

[42] It is an object of the present invention to provide a dental implant whereby the treatment will be easy with less insturmentation and increase success rate with excellent initial stability even in the poor quality bone. Technical Solution

[43] To achieve above mentioned object, the fixutre(lθ) have microthread(20) where it meets cortical bone area and have macrothread(22) where it meets cancellous bone. The apical portion of this particular implant fixture(lθ) has flat bottom and the body has conical shape with about 3-10° angle of inclination(θ). Also there are 2-4 grooves, long and short grooves(24a)(24b), and cutting edges on the macrothread portion of fixture. The long grooves(24a) are extended from right under microthread area to apex of fixture and the short grooves are arranged reciprocally and runs partway but do not extend up to apex.

[44] Also in this invention, fixture(lθ) has frusto-conical inclination(27b) above the internal hexagon(28) and screw hole wherein mating external hexed(30) healing abutment(12) can be assembled with using abutment screw. Hollow bodied(31) healing abutment(12) is provided with internal hexed part(32) on the top and a circum- ferentially continuous arcuate resess(34) is formed in the internal wall partway between the annular shoulder and upper hexed portion.

[45] In another embodiment, impression coping(14) which snap fits into healing abutment(12) comprise crucially incised annular club at its bottom and coaxially projected hexagonal portion, fitting into the internal hexed portion of healing abutment, and flange which seats on the annular shoulder of healing abutment. This part is connected with plastic cylindrical post(56) and tubular member where several flanges which have semi-circular channels(58a) exist.

[46]

Advantageous Effects

[47] This invention have advantages of increasing initial stability when operator place implant into jawbone of a patient and simplify complicated impression making procedure. Brief Description of the Drawings

[48] Fig. 1 to 8 illustrate different embodiments of this invention by way of example with reference to the accompanying drawings, of which; Fig. 1 shows perspective view of the assembled conditon of implant apparatus, Fig. 2 shows parts exploded view of Fig 1. Fig 3 is cross sectional view of side elevation of assembled condition of implant apparatus and Fig 4 is cross sectional view of side elevation of Fig 2.

[49] Fig. 5 is underneath plan view of fixture descrived in this invention.

[50] Fig. 6 is cross sectional view of fixture, healing abutment and hygienic cap.

[51]

Best Mode for Carrying Out the Invention

[52] Now, the present invention will be described in detail.

[53] The dental implant apparatus of the present invention comprises a fixture of which it's self drilling and tapping capability is increased so that operator can place fixture with less complicated and fewer instrumentation. Thus operator can save time to place implant and increase success rate due to increased initial stability.

[54] Fig. 1 or Fig 4 are assembled and part exploded view of impression coping to fixture described in this invention . Fig 1. is a assembled perspective view, Fig 2. is part exploded perspective view, Fig 3 is cross sectional view of side elevation of assembled condition of implant apparatus and Fig 4 is cross sectional view of side elevation of Fig 2.

[55] Fig. 5 is underneath plan view of fixture(lθ) described in this invention.

[56] The embodiment of implant apparatus (100) described herein comprise fixture(lθ), healing abutment(12) and impression coping(14). In some case higienic cap(16) can be placed instead of impression coping illustrated in Fig 6. [57] Fixture(lO) has microthreads herein called cortical portion(20) where it meets with cortical bone tissue layer and has macrothreads next to microthreads where it meets with cancellous bone tissue layer, said cancellous portion(22).

[58] The apical portion of cancellous portion(22) in this particular implant fixture(lθ) has flat bottom and the body has conical shape with about 3-10° angle of inclination(θ). Also there are 2-4 grooves, long and short grooves(24a)(24b). Thus several cutting edges(26) are created on the cancellous portion of fixture.

[59] If all 4 grooves (24a) (24b) described above are extended up to the bottom, apical portion lose its sharp cutting edge(26) due to width of grooves and subsequently lose self-tapping or self-drilling ability, and cannot fulfill their function fully.

[60] So in this invention, two pairs of diametrically opposing grooves(24a)(24b) are formed circumferentially at a right angle. But the long grooves(24a) are extended to the bottom of fixture and the short grooves(24b) are extended partway and it's length depends on the length and diameter of fixture(lθ).

[61] Fig. 5 shows the underneath plan view of fixture described in this invention and illustrates several cutting edges are formed with 4 grooves(24a)(24b), 2 long and 2 short grooves.

[62] Fixtures(lO) described above can have self drilling capacity due to increased self tapping ability with several cutting edge(26) explained in this invention. Operator can screw into patient's jawbone even at the undersized drilling hole by force. Thus implant placement procedure requires less instrumentation but can have better initial stability.

[63] In refer to fig 1. or fig 4., microthread formed at the cortical bone tissue layer(20) of fixture(lθ) can increase bone to implant contact ratio and can lead to better osseointe gration. Also these microthreads can distribute occlusal force transmitted to fixture evenly and have effect to lower maximum equivalent stress. Preferably, these microthreads on the cortical portion of fixture have 0.25mm ~ 0.35mm pitch, about 0.25mm thread height. And the angle between flanks of micrthreads is 60° in this preferred embodiment.

[64] And preferably, macrothreads formed at the cancellous portion of fixture have

0.6~0.9mm pitch, 6-30° angle between flanks and 0.3~0.5mm thread height.

[65] The implant further comprises an internal cavity with an opening located at the top surface. The internal cavity comprises a internal hexed chamber with frusto-conical in- clination(27b) from the top of fixture and screw hole. This frusto-conical inclination guides abutment placement.

[66] Also the top of fixture is inclined to the outwardly at an angle of 40°~

[67] 45°(27a).

[68] Preferably, it is better to blast fixture with mixture of bio-inert calcium and phosphate and clean with acid or try to increase the composion of calcium or phosphate or magnesium, or fluoride etc. in oxidized layer.

[69] In an embodiment of this invention, healing abutment(12) which is assembled to the top of fixture(lθ) is designed to make impression without removing it from the fixture. That is, the healing abutment described in this invention can be used as impression coping aid.

[70] Unlike conventional healing abutment, healing abutment described in this invention is hollow tubular post and hexagonal portion projecting coaxially from its smaller diameter. This hollow bodied(31) healing abutment(12) is provided with internal hexed part(32) on the top and a circumferentially continuous arcuate recess (34) is formed in the internal wall partway between the annular shoulder and upper hexed portion so that it can snap-fitted with impression coping(14) or hygienic cap(16) shown in Fig. 1 or 4. Preferably these healing abutment can be made of either titanium or plastic material.

[71] Once healing abutment(12) is inserted, it can be assembled with fixture(lθ) using abutment screw( not shown ).

[72] Hygienic cap(16) illustrated in Fig. 6 is an aid to close up an opening on the top of healing abutment(12). Preferably this hygienic cap can be used to stop up a tubular inside from foreign substance after healing abutment(12) is connected following implantation of fixture(lθ) or uncovering surgery. The exterior of hygienic cap comprise semi-circular shape top(44), hexed part(42) under head which mates with corresponding internal hex of healing abutment and crucially incised annular club(50) at the bottom. Preferably this hygienic cap is made of plastic material.

[73] If operator push hygienic cap(16) into helaing abutment, crucially incised annular culb(40) snap fits with corresponding circumferentially continuous arcuate recess(34) formed on the internal wall of healing abutment. At the same time, hexed part(42) of cap mates with corresponding internal hex(32) of healing abutment and make the cap to resist rotation.

[74] Impression coping illustated from Fig. 1 to 4 is a cylindrical post which is lock in place in the set impression material. It comprise crucially incised annular club(50) at its bottom and coaxially projected hexagonal portion(52), fitting into the internal hexed portion of healing abutment, and flange(54) which is seated on the annular shoulder of healing abutment. This part is connected with plastic cylindrical post(56) and tubular member where several flanges which have semi-circular channels(58a). There are several pairs of diametrically-opposed aperatures(62) exist between cylindrical post and top flange. Each aperture(62) extends through the tubular wall, communicating at its inner end with the bore.

[75] This impression coping(14) preferably made of plastic material to bend over in case it contacts with impression tray.

[76] To make implant impression with conventional method, operator have to remove healing abutment to insert conventional impression coping and assemble impression coping to fixture have to be verified through X-ray. After impression is taken, operator has to put the healing abutment back where it was. These procedure is very time consuming and cumbersome process.

[77] But in an embodiment of this invention, implant impression can be taken without removing healing abutment(12) from fixture(lθ) to make cumbersome process simple and save time.

[78] Operator can make impression after he or she remove snap-fitted hygienic cap(16) unlike conventional implant impression making method. The impression making procedure is as follows. First impression coping(14) need to be bent over not to touch impression tray and snap fitting the impression coping into helaing abutment(12). Then Standard impression tray filled with an impression material, such as an elastomeric material, inserted into the mouth of patient, over the teeth, gums and impression coping to create impression.

[79] The impression material is forced through the apertures(62) in the cylindrical portion.

[80] When impression material has set, the impression tray is removed from the jaw, to be exact from healing abutment(12), taking the impression material and coping(14) with it. Then the dental technician connect fixture replica with another same size healing abutment to put it back to the impression coping embedded in the impression and form replica of teeth and gums of patient. This procedure described in this invention simplify conventional complicated method of making the appropriate size of implant prosthesis to be made to the correct position. Mode for the Invention

[81] To achieve the objects mentioned in this invention, the annular club formed at the bottom of impression coping can be divided into 2 to 6 parts depending on the diameter. Also the bottom of healing abutment wherein connected with top of fixture can have internal hex depending on the fixture to be used. Industrial Applicability

[82] Although several embodiments were specifically exampled to achieve above mentioned objects, various modifications can be made by the person skilled in the art. So the relm of this invention should not be confined to the specific example described and should be decided what is claimed by the following.

[83]

Claims

[1] In an implant apparatus, comprise fixture and healing abutment, the fixutre(lθ) have microthread(20) where it meets cortical bone area and have macrothread(22) where it meets cancellous bone. The apical portion of this particular implant fixture(lθ) has flat bottom and the body has conical shape with about 3-10° angle of inclination(θ). Also there are 24 grooves, long and short grooves(24a)(24b), and cutting edges on the macrothread portion of fixture. The diametrically apposed two long grooves (24a) are extended from right under microthread area to apex of fixture and the two diametrically opposed short grooves are displaced angularly by a right angle from long grooves and runs partway but do not extend up to apex.

[2] In claim 1, fixture(lθ) has frusto-conical inclination(27b) above the internal hexagon(28) and screw hole wherein mating external hexed(30) healing abutment(12) can be assembled with using abutment screw. Hollow bodied(31) healing abutment(12) is provided with internal hexed part(32) on the top and a circumferentially continuous arcuate resess(34) is formed in the internal wall partway between the annular shoulder and upper hexed portion.

[3] In claim 2, impression coping(14) which snap fits into healing abutment(12) comprise comprise crucially incised annular club at its bottom and coaxially projected hexagonal portion, fitting into the internal hexed portion of healing abutment, and flange which is seated on the annular shoulder of healing abutment. This part is connected with plastic cylindrical post and tubular member thereon several flanges which have semi-circular channels.

[4] In claim 3, several diametrically opposed aperture are formed between plastic cylindrical post(56) and top flange(58) on the impression coping. Each aperture(62) extends through the tubular wall of the cylindrical portion, communicating at its inner end with the bore.

[5] In claim 2 or 3, The exterior of hygienic cap comprise semi-circular shape top(44), hexed part(42) under head which mates with corresponding internal hex of healing abutment and crucially incised annular club(50) at the bottom. Preferably this hygienic cap is made of plastic material.