JPH07184933A - Artificial dental root - Google Patents

Abstract

(57) [Summary] [Construction] In the artificial tooth root of the present invention, the fixture 1 is shortened to such an extent that the upper end surface thereof is located below the boundary between the alveolar bone and the gingiva, and the fixture 1 is provided above the fixture 1. The structure is such that the intermediate member 2 and the abutment member 3, which are embedded in the bone for a certain period of time together with the char 1, can be selectively and detachably fixed. In addition, at least the surface of the intermediate member 2 in contact with the bone is made of a material that is neither biohazardous nor bone-unionable, or is made of a metal material that is bone-unionable and has a mirror-like surface. [Effect] The gingiva is not sandwiched between the intermediate member and the mucosal surface of the denture, and the gingiva is not dehisced. Therefore, the tissue around the fixture is not infected with bacteria and loses bone fixation. Further, since the alveolar bone does not overhang on the upper end side of the intermediate member, there is no need to perform extra bone cutting, which is safe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for attaching an upper structure made of an artificial material such as an artificial crown to the oral cavity in a case where natural teeth must be extracted due to periodontal disease or the like. The present invention relates to an artificial root that is fixed by engaging with alveolar bone.

[0002]

2. Description of the Related Art Conventionally, there is a submerged type as an artificial tooth root, in which only the fixture is embedded in the alveolar bone, the fitting part of the upper part is closed with a cap, and then the gingiva is covered. After fixing the fixture to the alveolar bone stably for a few months, the gingiva is opened and the cap is removed, and the upper part of the fixture, such as an artificial crown, is placed on the upper side of the fixture. In order to attach the structure, the abutment member that penetrates the gingiva and projects into the oral cavity is screwed, and in such an artificial tooth root, as shown in FIG. 4, the upper end surface of the fixture F is Is placed so as to be located at the boundary between the alveolar bone B and the gingiva S, and an external screw F ₁ is formed around the fixture so as to engage with the bone, and at least the fixing force with the bone is further enhanced. Alveolar Bio active material having excellent surface in contact with the B to bone union, eg constituted by hydroxyapatite and further form the pores or irregularities on the surface thereof.

[0003]

However, in the above-mentioned conventional artificial tooth root, the contact area with the mucosal surface is adjusted so that the stress is not transmitted as much as possible through the gingiva S for the purpose of maintaining the fixture F under a small load condition. The denture is made to be used in the patient's daily life, but if the cap C is projected from the alveolar bone B to some extent, the gingiva S is sandwiched between the upper surface of the cap C and the mucosal surface of the denture, and the gingiva S is dehisted. , Fixture F
There was a problem that the tissues around the bones were infected with bacteria and lost their bone fixing ability.

On the other hand, even when such a problem does not occur, since the bone B overhangs on the upper side of the cap C and heals as shown in FIG. 5, the bone B overhangs when the abutment member is attached. It is necessary to excise and remove the bone, which is troublesome for the operator, and the bone is damaged excessively, resulting in excessive bone resorption.

[0005]

In order to solve the above problems, in the artificial tooth root of the present invention, the fixture is shortened so that its upper end surface is located below the boundary between the alveolar bone and the gingiva. On the upper side of the char, an intermediate member that is embedded in the bone together with the fixture for a certain period of time and, in place of this intermediate member, an abutment member that penetrates the gingiva from the alveolar bone and projects into the oral cavity can be selectively attached and detached. It has a structure that can be fixed.

[0006] At least the surface of the intermediate member that contacts the bone is made of a material that is neither harmful to bone nor bone-union, or is made of a metal material that has bone-union and has a mirror-like outer surface. .

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an artificial tooth root, 1 is a fixture preferably having a bone-coupling outer surface to be embedded and fixed in the alveolar bone, and 2 is attached to and detached from the upper end side of the fixture 1. An intermediate member which is free and is embedded with the fixture 1 in the alveolar bone for a certain period of time, and 3 is the intermediate member 2
Instead of the abutment member, which is fixed to the upper end side of the fixture 1 and has a tip portion protruding into the oral cavity, the tip portion of the abutment member 3 fixes an upper structure made of an artificial material such as an artificial dental crown. It is like this.

The fixture 1 has a cylindrical shape as a whole and mechanically engages with bones. Therefore, an outer screw 1a is formed in the lower portion and an intermediate member is formed by a screw hole 1d opened in the upper end surface 1c. 2 and the abutment member 3 can be selectively and detachably fixed.

The intermediate member 2 has a cylindrical shape as a whole and is formed with a bolt insertion hole 2b penetrating in the direction of the central axis. Further, the upper portion penetrates the bolt insertion hole 2b and has a bolt N. counterbore portion 2c of the deep opening to upper order to accommodate the head portion N ₁ is formed, so that it can be detachably fixed to the upper end of the fixture 1 by bolts N.

Further, when at least the surface of the intermediate member 2 in contact with the bone is made of a material that is neither biohazardous nor bone-unioning, or is made of a metal material having bone-unioning property,
The surface is treated as a mirror surface to give a non-bone-union outer surface.

The abutment member 3 has a truncated cone shape as a whole, and has a bolt insertion hole 3a and a counterbore 3 for fixing the bolt.
b is formed so that it can be fixed to the upper end side of the fixture 1 by a bolt L.

In order to fix the artificial tooth root 1 thus constructed by the alveolar bone B, as shown in FIG. 2, first, the fixture 1 is fixed to the alveolar bone B and the gingiva S with its upper end surface 1c.
Implant so that it is located below the boundary of
The intermediate member 2 is fixed with bolts N, and in this state, the upper side is covered with gingiva S.

At this time, some sizes of the intermediate member 2 are prepared so that the upper end of the intermediate member 2 does not project into the gingiva S, or the intermediate member 2 is shaped during the operation to be formed. Adjust so that the upper end of does not protrude into the gingiva S. As a result, it is possible to avoid a situation in which the gingiva S is sandwiched between the intermediate member 2 and the mucosal surface of the denture and the gingiva S is dehisced.
Therefore, the problem that the tissue around the fixture 1 is infected with bacteria and necrosed to lose bone fixation does not occur.

Subsequently, after covering the gingiva S, the upper gingiva S is opened after a certain period of time so that the fixture 1 and the alveolar bone B can be stably fused. At this time, since the intermediate member 2 has a non-bone-unioning outer surface that is not harmful to the living body, it does not directly bond with the alveolar bone B, and therefore, the alveolar bone B is partially stressed with excessive stress. It does not cause resorption or the alveolar bone B does not overhang on the upper end side of the intermediate member 2.

Finally, the fixture 1 to the intermediate member 2
, The abutment member 3 is screwed in place of the intermediate member 2 as shown in FIG. 3, and the tip portion thereof is projected into the oral cavity,
An upper structure made of an artificial material such as an artificial dental crown is attached to this.
At this time, since the alveolar bone B does not overhang on the upper end side of the intermediate member 2 as described above, it is not necessary to perform extra bone cutting.

In order to explain the material of each member constituting the artificial tooth root which acts in this way, the fixture 1 will be described.
Is a metal material having bone-bonding property as a whole, that is, pure titanium, titanium alloy, cobalt-chromium-molybdenum alloy, stainless steel, or at least the surface in contact with bone is Bone fusion metal material or HAP, TCP, OCP, polylactic acid,
It is preferable to use a material having a bone-union property such as carboxymethyl chitin, and it is preferable to form irregularities or pores on the surface in order to enhance the fixing force with bone.

Further, the intermediate member 2 is made of a material which does not cause biofouling and has no bone fusion at least on the surface in contact with the bone so as not to be fused with the bone. For example, as the ceramic material, single crystal alumina or polycrystalline alumina is used. , HDPE, silicon, polyvinyl alcohol, etc. can be used as the polymer material such as zirconia, silicon carbide, and carbon-based ceramics, or the surface of the metal material having the bone cohesive property is used as a mirror surface. be able to.

When at least the surface of the intermediate member 2 in contact with the bone is made of the above-mentioned material having no bone cohesion, the surface roughness of the surface is preferably 1 μm or less. That is, when the surface roughness is larger than 1 μm, the alveolar bone B and the irregularities on the surface are mechanically engaged with each other, which may cause the above-mentioned problems of bone resorption and bone overhang. Further, when the metal material having the bone union property is used, the surface roughness is 0.5.
It is preferably not more than μm. That is, if the surface roughness is 0.5 μm or less, the fixture 1 has the alveolar bone B.
Even if it is stably fixed inside, the fusion between the intermediate member 2 and the bone is very weak, and there is no risk of the above-mentioned problems of bone resorption and bone overhang. There is a possibility that the above-mentioned problems of bone resorption and bone overhang may occur due to large fusion.

When a ceramic material such as polycrystalline alumina or the above polymer material is used for the intermediate member 2, as shown in FIG. 3, a part of the intermediate member 2 is adjusted according to the thickness and shape of the patient's gingiva. It is possible to prevent the intermediate member 2 from protruding beyond the gingiva by shaping and cutting the pre-operatively or during the surgical operation, and the gingiva S is removed from the intermediate member 2
Therefore, there is no problem that the gingiva S is cleaved by the mucosal surface of the denture, the tissue surrounding the fixture 1 is infected with bacteria, and bone fixation is lost.

The abutment member 3 can be made of a material which is generally considered to have excellent adhesiveness and adhesion to soft tissue, such as titanium alloy.

[0022]

As described above, the artificial tooth root of the present invention is
The fixture is made short enough that its upper end surface is located below the boundary between the alveolar bone and the gingiva, and on the upper side of this fixture, the intermediate member and the intermediate member that are embedded in the bone for a certain period together with the fixture. Instead, the abutment member that penetrates the gingiva from the alveolar bone and protrudes into the oral cavity is selectively and removably fixed, so that the upper end of the intermediate member does not protrude into the gingiva. The member can be prepared, or the intermediate member can be adjusted during surgery so that the upper end of the intermediate member does not protrude into the gingiva. As a result, the gingiva is not sandwiched between the intermediate member and the mucosal surface of the denture, and the gingiva is not dehisced. Therefore, the tissue around the fixture is not infected with bacteria and loses bone fixation.

In addition, since at least the surface of the intermediate member that contacts the bone is made of a material that is neither biohazardous nor bone-unioning, or is made of a bone-unionting metal and treated as a mirror surface, It has a non-bone union outer surface.
Therefore, since the alveolar bone does not overhang on the upper end side of the intermediate member, it is not necessary to perform extra bone cutting and it is safe.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an artificial tooth root according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which an intermediate member is fixed to a fixture constituting the artificial tooth root of FIG. 1 and embedded in the alveolar bone.

FIG. 3 is a cross-sectional view showing a state in which an abutment member is fixed to a fixture that constitutes the artificial tooth root of FIG.

FIG. 4 is a cross-sectional view showing a state in which a fixture constituting a conventional artificial tooth root is embedded in alveolar bone.

FIG. 5 is a cross-sectional view showing a state in which a fixture constituting a conventional artificial tooth root is embedded in alveolar bone.

[Explanation of symbols]

1 Fixture 1a Outer screw 1c Upper surface 1d Screw hole 2 Intermediate member 2b Bolt insertion hole 2c Counterbore part N bolt N ₁ Head part 3 Abutment part 3a Bolt insertion hole 3b Counterbore part L Bolt S Gum B B Alveolar bone

Claims (1)

[Claims] 1. A fixture that is embedded and fixed in the alveolar bone, an intermediate member that is removable from the fixture and that is embedded with the fixture in the alveolar bone for a certain period of time, and in place of the intermediate member, An artificial tooth root that is fixed to the upper side of the fixture and is composed of an abutment member that penetrates the gingiva from the alveolar bone and projects into the oral cavity in order to attach an upper structure such as an artificial dental crown, wherein the intermediate member is at least An artificial dental root characterized in that the surface in contact with the bone is made of a material that is neither biohazardous nor bone-unioning, or is made of a metal material having bone-unioning and the surface is mirror-finished.