JP5450046B2 - Dental implant fixture - Google Patents

Description

The present invention relates to an artificial dental implant for prosthesis of a lost tooth, and relates to a fixture shape of an implant adapted to pressurization by a chewing function of a tooth.

  In order to regain the function of teeth lost due to dental caries and periodontal disease, as a means of supplementing oral functions lost by replacing with artificial materials such as metal and ceramics, dentures are buried in the root or completely lost to the root In such cases, there are treatment methods such as placing a denture with a bridge on healthy teeth. Furthermore, oral implant treatment is currently being implemented as one of the advanced treatments for this dental replacement medicine. Oral implant treatment is a means of implanting a titanium artificial tooth root in the jawbone at the site of the lost tooth.

  When implanting artificial roots in the jawbone of the lost tooth site, i.e., the alveolar bone, with normal artificial materials such as metal, the connective tissue of the alveolar bone surrounds and eliminates the artificial material, so the sway gradually increases and becomes artificial. The function as a tooth root was lost.

  In 1952, Sweden's Per Ingvar Brönemark accidentally discovered that titanium and bone were completely combined, and when titanium was implanted in the bone under certain conditions, bone rejection to titanium Did not occur at all, and it was revealed that a strong bond was born through the oxygen film covering the titanium surface. In 1965, the first clinical application as an artificial tooth root was started. Since then, oral implant treatment has made tremendous progress. The bone connection method, in which titanium and bone are directly connected without intervening connective tissue, is called osseointegration, which is a combination of Latin male (os) for bone and English integration for bone. It is.

  Osseointegration is a phenomenon in which bone and metal are directly bonded, and the force acting on the contact surface between the oxide film on the titanium surface and the bone bonds biological molecules to the oxide film to cause bone adhesion. Therefore, the success of implants is important in how to obtain osseointegration.

  Bone and teeth, which are inorganic substances, are mainly composed of hydroxyabatite. In order to promote the growth of osseointegration, a method of coating the surface of the fixture with hydroxyabatite has been proposed (for example, Patent Document 1). reference).

  When the implant is implanted in the body, the detection activity is started in the living body by macrophages and foreign substance detection cells in the living body in the living body against the foreign body's implantation, but it constitutes hydroxyapatite or the base of the implant It is said that when hydroxyapatite is coated on the surface of the metal material to be detected, these are close to the tissue composition of the bone, so the foreign substance detection cell is determined as a living tissue, and the cell-bone connection proceeds early. .

  As a consideration from the viewpoint of the mechanical stability of the fixture embedded in the alveolar bone, a shape device is also devised. In this case, excessive pressure results in bone resorption, but is based on Wolff's law, which says, “The bone strength is changed by remodeling the bone according to the mechanical demand of the bone.” There are several examples of geometrical considerations on how to avoid excessive pressure and how to disperse structurally to moderate pressure.

  If the root part of the fixture is basically cylindrical, this shape will not achieve the desired main stability after surgery of the fitted implant and will loosen in years. Come. This is because an excessive force is applied to the bone-bonded portion, resulting in bone resorption. For this reason, it is assumed that the straight cylindrical shape is not the most suitable shape. A shape having an outer contour (outer shape) has been proposed (see, for example, Patent Document 2).

  In addition, the masticatory function is proposed with a shape in which the bottom surface of the implant is horizontal, assuming that the maximum load is applied vertically to the implant (see, for example, Patent Document 3).

  Natural teeth have periodontal ligaments that are connected to the jawbone by band-bonded planting, and have a minute mobility function corresponding to mastication. Teeth with bone adhesion do not have this micro-mobility function and are always damaged by repeated pressurization. Therefore, artificial teeth with a shape that creates a fibrous tissue such as the original periodontal ligament after the artificial root is set up Proposals for tooth roots have also been attempted. The proposed artificial tooth root is a cylindrical shape having a crown at one end and a root apex at the opposite end, and bulges and depressions are alternately formed on the side surface along the axial direction. It is characterized (for example, refer to Patent Document 4).

In addition, the artificial tooth root has a double structure of an outer cylinder and an inner tooth root, and the outer cylinder and the inner tooth root are fixed with a resin adhesive, and the function of the original periodontal ligament is substituted with the resin adhesive as a cushioning material. There is also a proposal (see, for example, Patent Document 5).

Japanese Patent Laid-Open No. 2006-314760 Special table 2003-513684 literature Japanese Patent Laid-Open No. 2006-269558 Japanese Patent Laid-Open No. 6-154246 Japanese Patent Laid-Open No. 7-213540

  Osseointegrated implants based on osseointegration are prosthetic treatments that restore oral function resulting from dental defects. It is a system in which an implant is placed in the alveolar bone and directly connected to the bone, and the establishment and maintenance of osseointegration is essential for long-term success. For the establishment of this osseointegration, the factors resulting from the implant material, shape, and surface texture, as well as the bone state and load state, are important factors.

  The load state is considered to be the most important factor for maintaining the established osseointegration for a long time. This is because if the load state is inappropriate and there is a portion where the load is excessively concentrated on the alveolar bone around the implant, bone resorption occurs due to bone micro-damage and osseointegration is lost.

  Teeth are thought to be subject to loads from various directions, such as their masticatory function and toothbrushing, and because of their ability to chew food, the load cannot be controlled. Due to the target and shape effect, the shape to be distributed without concentrating the load must be considered.

The present invention relates to a fixture for an osseointegrated implant, which is a dental implant that can secure initial fixation by strengthening initial fixation, promoting osseointegration, avoiding excessive concentration on the load, and ensuring long-term stability. The purpose is to provide fixtures.

  The present invention includes a collar portion, a neck portion having a slight constricted portion, a main body portion that forms a part of a conical shape whose outer shape is gradually reduced from the neck portion, and a hemispherical or rounded apex portion. It is the fixture of the dental implant provided. The neck of the neck may be constricted in an arc shape or may have a shape having a straight side surface with a small outer diameter.

  When the collar part is not embedded in the alveolar bone, the outer diameter of the collar part and the upper end of the neck part is D1, the minimum outer diameter of the neck part of the neck part is D2, and the outermost part of the main body part is outside. When the diameter is D3, the relationship is D1 ≧ D3> D2. When a part of the collar portion is embedded in the alveolar bone, the outer diameter of the collar portion bottom surface and the upper end of the neck portion is D1, the minimum outer diameter of the neck portion of the neck portion is D2, and the maximum outer diameter of the main body portion is set. In the case of D3, the collar portion having the relationship of D3 ≧ D1> D2 and having the same outer diameter as the upper end of the neck is continuously connected to the neck, and the upper portion of the collar is made smaller than the outer diameter of the upper end of the neck. . Further, the length relationship has a relationship of L1 <L2 <L3 where the length of the collar portion is L1, the length of the neck portion is L2, and the length of the main body portion is L3.

  An implant consists of an upper rib structure (prosthesis), an abutment, and a fixture, but the fixture is embedded in the alveolar bone and is an attachment element from the upper rib structure configured as a pseudo tooth The occlusal force generated by mastication of the upper and lower teeth is loaded through the abutment. Since this load is applied not only in the vertical direction but also from the side, it is necessary to disperse the load from various directions and avoid the phenomenon of stress concentration on a part of the alveolar bone.

  For this purpose, the basic structure of the fixture is the main part of the fixture that forms a conical part with a gradually decreasing outer diameter following the neck part with a slight constriction from the collar part, and the fixture body. The apex, which is the end of the part, is hemispherical or rounded.

  This basic shape is a structure for dispersing stress against loads from various directions as well as the vertical direction. That is, when force is applied to the upper collar structure, the load on the upper end of the alveolar bone is distributed at the neck of the fixture neck, and the load is distributed at the bottom of the fixture by making the lower part an arc. I am trying.

  A plurality of flat plates with a sharp angle and a cross-sectional shape pointed outward from the neck are provided in close contact with the collar portion side region of the neck with slight constriction. This is a projection for bone stimulation using Wolff's law. The fine concavo-convex structure increases the contact area with the alveolar bone and fulfills the function of stress distribution. Further, the neck is provided with a region where no sharp flat plate is provided. This region facilitates correction of the direction of the implant by providing a minute space with the alveolar bone when the implant is placed. Further, in the long term, when bone resorption occurs, it has a role of improving the cleaning performance in a cleaning operation performed by incising the alveolar bone again.

  The outer diameter of the flat plate pointed outward from the neck is approximately equal to the outer diameter of the main body. Thereby, initial fixation can be performed stably. In addition to long-term stabilization due to the constricted structure and fine irregularities, the initial fixation can be performed sufficiently.

  From the main body portion of the fixture to the apex portion, a guide protrusion provided in a spiral shape is provided, and the fixture is embedded. Then, the outer diameter of the guide projection is made substantially equal to the maximum outer diameter of the main body portion to strengthen the initial fixation. Since the guide protrusion at the apex portion has a high height and a flat surface portion, the vertical force can be dispersed in the lower portion of the fixture.

  In order to stabilize the fixture with stable mechanical adaptability by dispersing the stress, the fixture surface is osseointegrated by coating with hydroxyapatite or blasting. It is also possible to prompt.

Since the collar part has a mirror-polished surface, osseointegration does not occur even if it is embedded in the alveolar bone, but since the part is embedded, it does not bond with the upper end of the alveolar bone. A part of the portion can be embedded in the alveolar bone to reduce the stress on the upper end of the alveolar bone.

The dental implant fixture according to the present invention provides sufficient initial fixation, disperses the load due to occlusion, prevents bone resorption, promotes osseointegration, and provides a stable implant over a long period of time. Has the effect of

The figure of the analysis model for analyzing the stress which an implant gives to alveolar bone. The figure which cut | disconnected the analysis model in the implant center part. The figure showing the alveolar bone part of FIG. The figure which shows Mises stress in the alveolar bone at the time of applying a 100N load. Alveolar bone part that becomes Mises stress of 10 GPa or more when 100 N load is applied. Fixture A according to the present invention. Schematic when the fixture A is embedded in the alveolar bone. Fixture B according to the present invention. Fixture C according to the present invention. Fixture D according to the present invention. Schematic when the fixture D is embedded in the alveolar bone up to a part of the collar portion.

  Although the implant is used as a substitute tooth, an occlusal force is applied to the fixture from the upper heel structure via the abutment by the occlusal action by mastication. Since the fixture is embedded in the alveolar bone, the load applied to the upper jaw structure is transmitted from the fixture to the alveolar bone, and stress is generated in the alveolar bone. When this stress is an appropriate value, the alveolar bone is regenerated and strengthened according to Wolff's law, but when an excessive occlusal force is applied, it causes bone destruction and resorption, and eventually fails.

  For this reason, it is necessary to grasp the stress generated in the alveolar bone due to the occlusal pressure on the implant, and to make it a shape in which the stress is not concentrated.

  FIG. 1 shows an analysis model 10 by a finite element method for performing stress analysis on an alveolar bone by an implant. Here, the purpose is to clarify the relationship between the shape of the fixture that is the portion of the implant embedded in the alveolar bone 12 and the stress, and the implant model 14 is obtained by adding an abutment to the fixture. In FIG. 1, the mesh in the alveolar bone 12 is a mesh in which element division is made finer than other parts in order to analyze the stress in the vicinity of the implant model 14 in detail. The X axis, Y axis, and Z axis are as shown in FIG.

  FIG. 2 shows a cross section of the analysis model 10. The center of the implant model 14 is cut. FIG. 3 shows only the portion of the alveolar bone 12 from which the implant model 14 is removed from the cut surface of the analysis model 10 of FIG. The implant model 14 is configured by integrating an abutment and a fixture. The abutment part 14-1 has a shape obtained by cutting the upper part of the cone, the fixture part 14-2 has a cylindrical shape, and the root apex at the bottom part has a rounded shape to model a general fixture shape. It is a thing.

  The actual analysis is performed using this half-section analysis model. This is because the number of meshes is reduced to reduce the effective capacity of the computer, and the calculation speed is improved.

  The elements of the analysis model are continuous, and the joint between the implant model 14 and the alveolar bone 12 is assumed to be completely adhered. As for the interface part of the actual implant, connective tissue exists in the cortical bone and sea surface bone, and in addition, in the case of titanium, the connection between the implant and the surrounding tissue is due to the relationship between the implant surface material and the bone and titanium. Some point out that it is a physical joint with an amorphous structure in between, and hydroxyapatite is chemically bonded to bone.

  However, since the fixture part of an implant is basically a metal and the shape of the fixture interface does not change, the mechanical stress relationship on the fixture-shaped alveolar bone is analyzed independently of the bonding state. Can be considered. That is, the influence of the fixture shape on the stress can be grasped regardless of the coupling state, and is sufficient for considering the optimum fixture shape of interest.

  In the analysis model 10 based on the finite element method, a Mises stress was calculated by applying a force of 100 N to the upper part of the abutment by tilting it downward by 45 degrees from the vertical. The implant model 12 was considered as titanium as a whole, and the Young's modulus was 116 GPa and the Poisson's ratio was 0.3. The alveolar bone 12 was made of a uniform material with a Young's modulus of 0.23 GPa and a Poisson's ratio of 0.4.

  The stress has 6 components in total of 3 components of normal stress and 3 components of shear stress. One scalar value by Mises stress is obtained and displayed for each mesh.

  The load on the implant model 12 is applied in the positive direction of the X axis, 45 degrees below the vertical. At this time, in order to avoid displacement of the entire model, the bottom surface portion was used as a restraint point in the analysis model of FIG.

  FIG. 4 shows an analysis result of Mises stress applied to the alveolar bone. Concentrated on the neck and apex of the fixture, the maximum was 14.22 GPa, and the minimum was 0.073 GPa at the alveolar bone bottom.

  FIG. 5 shows a Mises stress portion of 10 GPa or more. Assuming that the portion of 10 GPa or more due to repeated load is the limiting stress, and the portion shown in FIG. 5 is absorbed by the alveolar bone, the Young's modulus of this portion is reduced due to the collapse of the alveolar bone, and another portion The stress concentrates on the implant and gradually absorbs the alveolar bone around the implant, eventually leading to the failure of the implant.

  From the analysis result of the stress on the alveolar bone of the fixture by the finite element method, in the shape of the fixture portion 14-2 of the conventional implant, the top of the alveolar bone and the bottom alveolar bone corresponding to the apex of the fixture The stress was concentrated.

  Therefore, it is necessary to devise the shape of the top and bottom of the fixture to distribute the stress, and the embodiment of the dental implant fixture according to the present invention will be described in detail with reference to the drawings.

Example 1
FIG. 6 shows an embodiment according to the present invention in which stress is dispersed by devising the shape of the fixture. In the fixture A20, the bottom portion of the cylindrical collar portion 22 is connected to the neck portion 24, and the neck portion 24 forms an arc-shaped constricted portion. After passing through the maximum diameter portion 27 which is the maximum diameter of the fixture body portion 26 from the constricted portion, the cone portion 28 gradually decreases in diameter thereafter, and the apex portion 28 which is the end of the body portion 26 is The shape is almost semicircular. A female screw (not shown) for screwing the abutment is formed at the center of the collar portion 22 over the fixture main body.

  If the outer diameter of the upper end of the collar portion 22 and the neck portion 24 is D1, the minimum diameter of the constricted portion of the fixture neck portion 24 is D2, and the maximum diameter of the fixture main body portion 25 is D3, the relationship is D1 ≧ D3> D2. Yes. Further, assuming that the length of the collar portion 22 is L1, the length of the fixture neck portion 24 is L2, and the combined length of the fixture main body portion 26 and the apex portion 28 is L3, the relationship is L1 <L2 <L3. .

  The dimensions of the actually manufactured fixture A20 are D1 = 4 mm, D2 = 3.3 mm, D3 = 3.64 mm, L1 = 1.7 mm, L2 = 2.7 mm, and L3 = 7.8 mm.

  From the result obtained by the finite element method, concentrated stress is applied to the straight neck portion of the fixture, but in the shape of the fixture A20 according to the first embodiment of the present invention, the neck portion of the fixture neck 24 is constricted. And the stress is distributed. In addition, the fixture body 26 has a conical shape with a slightly narrower diameter, and disperses the stress applied vertically along with the hemispherical shape of the apical portion 28.

  The shape of the fixture A20 has a stress dispersion effect even with respect to the load from the side surface of the abutment. The fixture neck 24 that acts on the load from the side of the abutment has a constricted portion, and the stress is distributed along with the conical main body and the semicircular apex that serves as a fulcrum for the load. Shape.

  FIG. 7 is a view showing a state in which the fixture A20 according to the present invention is embedded in the alveolar bone. The fixture A20 is embedded in the alveolar bone up to the fixture neck 24, and the collar portion 22 faces the gingival portion 16.

  In addition to the geometrical effect on the load, the effect of promoting osseointegration is also produced by applying a hydroxyapatite coating or blasting to the fixture surface.

(Example 2)
FIG. 8A shows a shape of the fixture A20 shown in FIG. 6 in which a flat plate 32 having a cross-sectional shape that is pointed outwardly from the neck is formed in a partial region above the collar portion of the fixture neck 24. A plurality of fixtures B30 are provided in close contact with each other. An enlarged view of the multi-plate portion is shown in close contact with FIG. The protrusions 32-1 to 32-5 may be continuously provided in a screw shape. As a structure in which the protrusion stimulates the alveolar bone, the generation of alveolar bone is promoted by bone stimulation according to Wolff's law. The fine concavo-convex structure increases the contact area with the alveolar bone and also functions to distribute stress.

  The outer diameter of the flat plate pointed outward from the neck is made substantially equal to the outer diameter R33 of the main body. In addition, the size of the fixture B30 actually prototyped is the same as the size of the fixture A20, the pitch of the protrusions on the flat plate is 0.17 mm, and the width on the collar portion 22 side is 1.4 mm wide. Provided in the area. The constricted portion of the fixture neck portion 24 is substantially equal to the outer diameter R33 of the main body portion by the projections 32-1 to 32-5, and thereby, initial fixation when the implant is implanted can be stably performed. In addition to long-term stabilization by promoting osseointegration with a constricted structure and fine irregularities, it also has an effect on initial fixation stabilization.

  In the lower region of the neck portion 24, a region without a sharp flat plate is provided. If bone resorption occurs over a long period of time, the alveolar bone may be reopened and cleaned, and the treatment of the implant may be required. This makes it easier to clean the outer periphery of the implant. It has a structure. This is because providing a protruding flat plate on all necks makes it difficult to clean the outer peripheral surface.

  Also in Example 2, the surface of the fixture B30 may be subjected to a hydroxyapatite coating or blasting treatment, thereby causing an effect of promoting osseointegration.

(Example 3)
FIG. 8 shows the shape of the fixture B30 shown in FIG. The shape of the fixture C40 is shown.

  The outer diameter of the spiral guide protrusion 42 provided between the fixture main body 26 and the apex 28 is substantially the same as the maximum diameter R3 of the fixture main body. As a result, the height of the guide protrusion 42 increases toward the apex 28 as the guide protrusion extending from the fixture main body 26 that slightly narrows toward the apex 28 and the substantially hemispherical apex 28. The planar part becomes wider and the vertical force can be distributed in the lower part of the fixture.

  Furthermore, since the guide protrusion 42 has a male screw structure, the fixture C40 can be easily embedded by screwing, and the initial fixation can be further stabilized. Also in Example 3, it is needless to say that the effect of promoting osseointegration may be produced by applying hydroxyapatite coating or blasting to the surface of the fixture C40.

  The fixture C40 has sufficient effects that initial fixation can be sufficiently performed, and that load due to occlusion can be dispersed to prevent bone resorption, and osseointegration can be promoted to achieve stable implants over a long period of time. .

Example 4
FIG. 10 shows a fixture D50 of a type in which a part of the collar portion 22 is embedded in the alveolar bone. FIG. 11 shows a state where the fixture D is embedded in the alveolar bone.

  In FIG. 10, the collar portion 22 is mirror-polished and osseointegration does not occur, so the collar portion and the alveolar bone are not joined. By utilizing this property, a phenomenon in which the load concentrates on the upper end portion of the alveolar bone is avoided, and the load is applied to the inside of the alveolar bone. For this reason, the outer diameter D1 at the upper end of the neck portion 24 is the same as or slightly smaller than the maximum outer diameter D3 of the fixture body. The upper end portion outer diameter D4 of the collar portion 22 is smaller than the outer diameter D1 of the upper end portion of the neck so that the upper end portion of the alveolar bone can cover the neck portion.

  The collar portion 22 is connected to the upper end portion by gradually reducing the outer diameter of the upper end portion of the neck portion 22. The tapered shape of the collar portion 22 needs to be a shape that allows the upper end portion of the alveolar bone to cover the neck portion 24, and therefore may have a cylindrical shape smaller than the outer diameter D <b> 1 of the upper end portion of the neck portion 24.

  In this embodiment, the constricted portion of the neck portion 24 has a cylindrical shape having an outer diameter D2 that is smaller than the maximum outer diameter D3 of the fixture body portion 26. A part of the neck portion 24 on the side of the collar portion 22 is provided with a region of a protruding plate portion 24-1 provided with a sharp flat plate 32 and a region of a neck cylindrical portion 24-2 without the sharp flat plate 32.

  Further, the maximum outer diameter portion 27 of the fixture body 26 is provided with a boundary protrusion 52 that separates the neck 24 and the fixture body 26. Further, the guide protrusion 42 is also provided in a spiral shape to assist the insertion of the fixture D50.

  The actual dimensions of the prototype were as follows: the outer diameter D4 of the upper end of the collar portion is 3.5 mm, the length L1 of the collar portion 22 is 1 to 1.5 mm, and the neck portion 24 is 2.9 mm in length L2. The length of the flat plate portion 24-1 is 1.2 mm, the length of the cervical cylindrical portion 24-2 is 1.7 mm, and the length of the fixture main body portion 26 is 6.9 mm. The pitch of the protruding flat plates 32 is 0.17 mm. Further, it is desirable that the embedding amount of the collar portion 22 is about 0.5 mm.

  The fixture D50 embeds a part of the collar portion 22. However, if the outer diameter of the upper end portion of the neck portion 24 is slightly smaller than the maximum outer diameter D3 at the time of embedding, the direction of the fixture 50 is corrected. It can be made easier. In general, when a fixture is embedded, the direction may not be the desired direction from the beginning, and fine adjustment may be required. In such a case, the fixture D50 makes it easy to adjust the direction by using the minute gap in the upper part.

  Implants are required to have long-term stability, but in some cases bone resorption occurs and the alveolar bone must be incised to clean the fixture. In such a case, the cervical cylindrical region 24-2 below the cervical portion 24 has an effect of facilitating the cleaning operation. This is because if the protruding flat plate 32 is in the entire region of the neck portion 24, the time required for cleaning the surface becomes longer.

  Further, a boundary projection 52 is provided at the boundary between the neck 24 and the fixture body 26. This is a guideline for positional cleaning when bone resorption occurs from the upper part of the fixture when the state of the implant is observed by X-ray after a long period of time.

  The fixture D50 described in the present embodiment has a fixture shape that improves the workability of the dentist with long-term stabilization against stress.

As mentioned above, although the Example of this invention was described, this invention contains the appropriate deformation | transformation which does not impair the objective and advantage, Furthermore, the limitation by said embodiment is not received.

DESCRIPTION OF SYMBOLS 10 Analytical model 12 Alveolar bone 14 Implant model 14-1 Abutment part 14-2 Fixture part 16 Gingival part 20 Fixture A
22 Collar section 24 Neck section 24-1 Protruding flat plate section 24-2 Neck section cylindrical section 26 Fixture body section 27 Maximum diameter section 28 Apex section 30 Fixture B
32, 32-1-5 Projection 40 Fixture C
42 Guide protrusion 50 Fixture D
52 Boundary protrusion

Claims (10)

The color part,
It has a constricted portion, and has an area in which a plurality of flat plates with sharp tips at the tip and a sharp cross section outside the neck portion are provided in close contact with the upper portion on the collar portion side, and a region where no sharp flat plate is provided. The neck,
A body portion forming a part of the conical shape of the small fence outline from said neck,
Hemispherical or rounded root apex,
Dental implant fixture with The dental implant fixture of claim 1,
When the outer diameter of the collar part and the upper end of the neck part is D1, the minimum outer diameter of the neck part of the neck part is D2, and the maximum outer diameter of the main body part is D3, the relation of D1 ≧ D3> D2
A dental implant fixture characterized by The dental implant fixture of claim 1,
When the outer diameter of the upper end of the neck is D1, the minimum outer diameter of the constricted portion of the neck is D2, and the maximum outer diameter of the main body is D3, the relation of D3 ≧ D1> D2 is satisfied.
A dental implant fixture characterized by The dental implant fixture of claim 3,
The collar portion is continuously connected to the neck portion with the same bottom portion as the outer diameter of the upper end of the neck portion, and the upper portion of the collar portion is smaller than the outer diameter of the upper end portion of the neck portion;
A dental implant fixture characterized by In the fixture of the dental implant in any one of Claims 1 thru | or 4,
When the length of the collar portion is L1, the length of the neck portion is L2, and the length of the main body portion is L3, the relationship has L1 <L2 <L3,
A dental implant fixture characterized by The dental implant fixture of claim 5 ,
The outer diameter of the flat tip, it correct etc and the maximum outer diameter of the body portion,
A dental implant fixture characterized by In the fixture of the dental implant in any one of Claims 1-6 ,
From the main body part to the apex part, it is provided with a guide protrusion provided in a spiral shape,
A dental implant fixture characterized by Oite the fixture of the dental implant according to claim 7,
The outer diameter of the guide protrusion is equal to the maximum outer diameter of the main body,
A dental implant fixture characterized by

In the fixture of the dental implant in any one of Claims 1-8 ,
Coating the outer peripheral surface of the fixture with hydroxyapatite,
A dental implant fixture characterized by In the fixture of the dental implant in any one of Claims 1-8 ,
Blasting the outer peripheral surface of the fixture,
A dental implant fixture characterized by