JPH0819555A - Artificial tooth root - Google Patents

Abstract

PURPOSE:To provide an excellent self-cutting ability to an artificial tooth root which has a sufficiently high strength and an excellent rotation-checking ability so as to be stable. CONSTITUTION:An anchor part 1 of an artificial tooth root is tapered, and is formed at its outer peripheral surface with threads 3, and the longitudinal cross section of the anchor part 1 is defined by a quadratic curve so that the contour of the surface excepting the threads bulges outward, and a series of notches 4 are formed, having its length greater than intervals 5 of the notches, in the threads 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved artificial tooth root, and more particularly, it comprises an anchor portion to be embedded in the jaw bone and a neck portion integrally provided at the base end thereof, and imparts machinability during tapping. Therefore, the present invention relates to improvement of an artificial tooth root having a thread on the outer peripheral surface of the anchor portion.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Publication No.
Various types have been developed, as can be seen in JP-A-15905, JP-A-3-176045 and the like. Particularly, as those having a thread on the outer peripheral surface, those having a thread on the cylindrical surface as shown in FIG. 7A, and those having a frustum-shaped outer peripheral surface as shown in FIG. 7B. Those provided with are known.

In the case where the thread is provided on the cylindrical surface, the compression or extraction strength after implantation is improved, and a hole having a diameter approximately equal to the screw diameter is formed in the jawbone and is embedded therein. Therefore, the machinability due to screw threads is not so expected. Further, in the case where a trapezoidal outer peripheral surface is provided with a screw thread, cutting to some extent by the screw thread is expected due to the tapered shape, but there are problems as described below.

[0004]

That is, in the case where the frustum-shaped outer peripheral surface is provided with a screw thread, the machinability at the time of tapping cannot be said to be sufficient, and there is a problem in terms of the fixing strength, particularly the anti-rotation resistance. Therefore, means such as providing an axial groove a or a recess at an appropriate position has been adopted. Further, the conical shape has a problem in that the strength of the tooth root itself is low, and the compression resistance is low, and the tooth root may be immersed in the jawbone.

An object of the present invention is to solve the above-mentioned problems of the prior art, and therefore, it is excellent in machinability at the time of tapping, and has high strength and high stability in fixation to the jawbone. To provide the roots.

[0006]

In order to achieve the above object, an artificial dental root according to the present invention is provided with an anchor portion to be embedded in a jaw bone and a tooth integrally provided at a base end of the anchor portion and by screw engagement. It consists of a neck portion with a screw hole on the axis for attaching the crown mounting holder, the anchor portion is tapered toward the tip, and a screw thread is provided on the outer peripheral surface. In order to improve the tooth root, the longitudinal cross section of the anchor portion is a quadratic curve so that the contour of the surface excluding the thread bulges outward, and the thread has a series of notches. It is characterized in that the notches are provided so that the length of the notches is equal to or greater than the interval between the notches.

A preferred embodiment of the present invention is characterized in that the cross section of the thread on the outer peripheral surface of the anchor portion is triangular.

In another preferred form, the neck portion is characterized in that the cross section of the portion adjacent to the anchor portion is non-circular, and more preferably the non-circular shape is elliptical.

In another preferred embodiment, the neck portion has a circular cross section except the portion adjacent to the anchor portion and has a diameter smaller than that of the base end of the anchor portion.

In still another preferred embodiment, as a crown mounting holder, a screw which engages with the screw hole in the neck portion is provided in the lower portion, a screw hole is provided in the center of the upper portion, and the inner circumference is circular. An outer periphery of an elliptical key holder and the keyer at the bottom.
It is characterized in that it has a screw that engages with the screw hole of the holder, and that the upper part includes a magnetic magnetic keyer of a circular shape fitted into the inner circumference of the upper end of the keyer holder. .

[0011]

This artificial tooth root has compressive strength because the anchor portion has a quadratic contour and does not immerse. The notch is formed in the taper thread on the outer peripheral surface. It has excellent machinability. Further, since the length of the notches is equal to or longer than the interval between the notches, the bone fragments collected in the notches become a part of the new bone and are thus firmly fixed.

If the cross section of the thread of the anchor portion is triangular, the screwing during tapping becomes easier and the machinability is improved.

If the cross section of the portion of the neck portion adjacent to the anchor portion is non-circular, it becomes easy to apply torque by attaching a tightening tool to that portion, and the portion is oval. If it is shaped, it makes good contact with its surroundings.

If the diameter of the neck portion is smaller than that of the base end of the anchor portion, new bone formation at the neck portion will be facilitated and the root of the tooth will be fixed easily and firmly.

Further, if a cap holder having an elliptical outer circumference and a magnet caper made of a magnetic material fitted therein is provided as a holder for mounting a crown, the crown equipped with a magnet can be mounted. This is easily possible and the directionality of the caper holder can be easily confirmed.

[0016]

Embodiments of the present invention will now be described with reference to the drawings. 1 to 3 show a preferred example of this artificial tooth root, and the artificial tooth root of the present invention has an anchor portion 1 to be embedded in a jawbone as shown and its proximal end, that is, when it is embedded. It is constituted by the neck portion 2 integrally provided at the end portion located on the surface side of the jawbone, and is preferably made of titanium. In one example, the anchor has an axial length of about 7 mm and a maximum diameter of about 4 mm. As shown in FIG. 1, the anchor portion 1 is tapered toward the tip, and a thread 3 is provided on the outer peripheral surface 1a thereof.

One feature of this artificial tooth root is that it is tapered toward the tip, and the contour of the longitudinal cross section of the anchor portion, that is, the shape of the outer peripheral surface except the thread 3 bulges outward. That is, it is a quadratic curve. This tapered shape enhances the self-cutting property in combination with the notch of the screw thread, and the contour is a quadratic curve to enhance the strength of the anchor portion and to prevent the compressive force applied to the tooth root. The resistance is strengthened, and it is prevented from being embedded or immersed in the bone together with the thread 3. It is preferable that the outer peripheral surface 1a of the anchor portion converges at the tip, which has the advantage of producing cutting performance at the tip.

Another major feature of the present invention is that the thread 3 is formed with a series of notches 4 so that the length of the notches is not less than 5 between the notches, thereby improving self-cutting property. And the fixing property was remarkably improved. The shape of the notch 4 does not need to be particularly limited, and is formed in an arc shape as shown in FIG. 3, for example.

As shown in FIG. 3, the relation between the notch 4 and the interval 5 between the notches is that the circumferential length of the notch is b,
When the length of the interval is c, 1 ≦ b / c is adopted to satisfy both machinability and fixability, and preferably b / c.
Limited to <3. In one example, the thread height is 0.4 mm,
b = 1.5 mm and c = 1.0 mm. Note that b / c
This is because if 3 is set to 3 or more, the meaning as a thread is lost.

By thus setting the length of the notches 4 to be not less than the interval between the notches, a relatively large number of notches 4 are formed in the thread 3 and the contour of the anchor portion is tapered. In addition to the shape, the edges of each notch are involved in cutting, which significantly enhances self-cutting property. Further, after the implantation, the bone debris generated by cutting enters each notch 4, and these bone debris coalesces with the new bone and plays a role of fixing, thus firmly fixing the root of the tooth, Increase the detent. Bone strips placed in the valleys between the threads 3 coalesce with the new bone to enhance resistance to slippage and compression.

Further, the cross section of the thread 3 itself is preferably triangular as shown in FIG. 1, which has an advantage that the screwing resistance at the time of tapping can be reduced and the machinability can be improved. The thread pitch is set to an appropriate dimension according to various conditions.

In the artificial tooth root of the present invention, as shown in FIGS. 1 and 2, the portion 2 of the neck portion 2 adjacent to the anchor portion 1 is used.
The cross-section of a is formed non-circular, particularly preferably oval as shown, which facilitates torque loading during insertion. Further, if it is an elliptical shape, it has no corners, so there is an advantage that it has good contact with the surrounding bone.

As shown in FIGS. 1 and 2, the artificial tooth root preferably has a neck 2 having a circular cross section except for a portion adjacent to the anchor portion 1 and a base end 1b of the anchor portion. It has a smaller diameter, which facilitates new bone formation at the neck.

When implanting the artificial tooth root in the jawbone, a hole having a diameter smaller than that of the artificial tooth root is formed at a predetermined position of the jawbone by a drill or a punching machine, and the tooth root is inserted thereinto, and a portion of the neck portion 2 is formed. 2a is gripped with a tool and inserted while applying torque. This artificial tooth root is inserted to a predetermined depth while cutting the jawbone by the self-cutting property of the tapered shape and the thread 3 and the notch 4, and is installed at that position. Bone debris generated during the cutting enters between the threads 3 and each notch 4 and merges with the new bone to fix the tooth root.

A holder for mounting a crown is installed on the artificial tooth root, so that a screw hole 6 is formed on the axis of the neck portion 2. FIG. 4 shows an artificial tooth root provided with such a holder, and a preferred form of the holder is a caper holder-7 which is attached to the screw hole 6 by screw engagement.
And a magnet caper 9 made of a magnetic material, which is attached to the caper holder by screw engagement, and a magnet provided in the crown is attached to the magnet caper 9 by its magnetic force. It is installed by being adsorbed.

Therefore, as shown in FIGS. 5 and 6, the capper holder 7 has a screw 7a which engages with the screw hole 6 at the bottom thereof.
An annular portion 7 having a circular inner circumference and an elliptical outer circumference at the top
b, and there is a screw hole 8 on the upper axis. Further, the magnet keyer 9 has a screw 9a which engages with the screw hole 8 in the lower portion and a disc portion 9b which is fitted in the annular portion 7b in the upper portion. The use of such a holder facilitates installation of the crown on the artificial tooth root.

[0027]

As described above, in the artificial tooth root according to the present invention, the contour is tapered with a quadratic curve, and a series of notches is formed in the thread with a length not less than the interval between the notches. As a result, the root itself has sufficient strength and resistance to compression, as well as excellent self-cutting properties, and is also properly fixed, especially with excellent anti-rotation performance and high stability. .

Further, by making the cross section of the screw thread triangular, the screwing is made easier and therefore the self-cutting property is further improved.

Further, by making the cross-section of the neck portion adjacent to the anchor portion non-circular, the load of torque is facilitated, and this root implantation is facilitated.

By making the non-circular shape of the neck portion into an elliptical shape, torque loading is facilitated, and contact with the peripheral portion is improved, thereby improving the usefulness.

By making the neck portion smaller in diameter than the base end of the anchor portion, new bone formation around the neck portion is facilitated and the fixation is strengthened.

Further, the crown mounting holder is a magnetic key holder made of a magnetic material and a caper holder having an oval outer periphery.
By configuring with a par, the crown can be easily and properly attached, and the orientation can be easily confirmed.

[Brief description of drawings]

FIG. 1 is a side view showing an artificial tooth root according to an example of the present invention.

2 is a plan view of the artificial tooth root shown in FIG. 1. FIG.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a side view, partially in section, of an artificial tooth root of the present invention provided with a holder for mounting a crown.

5A and 5B are holders for mounting a crown.
FIG. 3 is a vertical cross-sectional view and a plan view of a caper holder that constitutes a part of FIG.

6 (a) and 6 (b) are holders for mounting a crown.
5A and 5B are a side view and a plan view of a magnet caper constituting another part of FIG.

7A and 7B are side views showing a conventional artificial tooth root.

[Explanation of symbols]

 1 anchor part 2 neck part 3 screw thread 4 notch 5 part between notches 6 screw hole 7 keyer holder 8 keyer holder screw hole

Claims (6)

[Claims] 1. An anchor portion to be embedded in a jaw bone and a base end of the anchor portion are integrally provided, and a screw hole is provided on an axis for mounting a crown mounting holder by screw engagement. An artificial tooth root comprising a neck portion, wherein the anchor portion is tapered toward the tip thereof and a thread is provided on the outer peripheral surface thereof, and the longitudinal cross section of the anchor portion excludes the thread. The contour of the surface is a quadratic curve so as to bulge outward, and a series of notches is provided in the thread so that the length of the notches is equal to or greater than the interval between the notches. An artificial tooth root characterized by being present. 2. The artificial tooth root according to claim 1, wherein the cross section of the thread has a triangular shape. 3. The neck section has a non-circular cross section in a portion adjacent to the anchor section.
An artificial tooth root according to the item. 4. The artificial tooth root according to claim 3, wherein the non-circular shape is an elliptical shape. 5. The neck portion has a circular cross section except for a portion adjacent to the anchor portion, and has a diameter smaller than a base end of the anchor portion. Artificial tooth root. 6. The crown mounting holder further has a screw which engages with the screw hole of the neck portion at the lower portion, has a screw hole at the center of the upper portion, and has a circular inner circumference and an elliptical outer circumference. Key
A key holder, and a lower part having a screw engaging with a screw hole of the keyer holder and an upper part having the keyer holder.
The artificial tooth root according to claim 1, further comprising a circular magnet capper made of a magnetic material and fitted into the inner circumference of the upper end.