JP3342960B2 - Artificial root - Google Patents

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, to an improved artificial tooth root comprising an anchor portion 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 an improvement of an artificial tooth root having a thread on an outer peripheral surface of an anchor portion.

[0002]

2. Description of the Related Art Conventionally, as an artificial tooth root, for example,
Various types have been developed as shown in JP-A-15905, JP-A-3-17645 and the like. In particular, those having a thread on the outer peripheral surface include those having a thread on a cylindrical surface as shown in FIG. 7A, and those having a thread on the frustum-shaped outer surface as shown in FIG. And the like are known.

[0003] In the case where a thread is provided on a cylindrical surface, the compression or pull-out strength after implantation is improved, and a hole having a diameter approximately equal to the screw diameter is formed in the jaw bone and embedded therein. Therefore, the cutting property by the thread is not expected much. Further, in the case where a thread is provided on the outer peripheral surface of a truncated cone, cutting by the thread is expected to some extent due to the tapered shape, but has the following problems.

[0004]

That is, when a thread is provided on the outer peripheral surface of a frustum-shaped cone, it cannot be said that the cutting property at the time of tapping is sufficient, and there is a problem in terms of fixing strength, particularly, resistance to rotation. Therefore, means such as providing an axial groove a or a depression at an appropriate position have been adopted. Further, the conical shape has a problem in that the strength of the tooth root itself is problematic, and the compression resistance is low and the tooth root is immersed in the jaw bone.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and therefore, it is excellent in cutting property at the time of tapping, and has high strength and high stability in fixing to a jaw bone. To provide the roots.

[0006]

In order to achieve the above object, an artificial dental implant according to the present invention is provided with an anchor portion to be implanted in a jaw bone, and is integrally provided at a base end of the anchor portion and is screwed to engage the tooth. An artificial head having a neck portion provided with a screw hole on an axis for mounting a crown mounting holder, and an anchor portion tapered toward its tip and having a thread on its outer peripheral surface. In order to improve a tooth root, a longitudinal section of an anchor portion has a quadratic curve so that a contour of a surface excluding a thread is bulged outward, and a series of notches are provided in the thread. It is characterized in that the notches are provided such 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.

[0008] In another preferred form, the neck portion has a non-circular cross section at a portion adjacent to the anchor portion, and more preferably the non-circular shape is elliptical.

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

In a further preferred form, the crown mounting holder has a screw at a lower portion for engaging with the screw hole of the neck portion, a screw hole at the upper portion at the center, and a circular inner periphery. An outer periphery is a keyer holder having an elliptical shape, and a lower portion is provided with the keyer.
The holder is characterized in that it has a screw for engaging with a screw hole, and the upper part includes a magnetic magnetic keeper made of a circular magnetic material fitted into the inner periphery of the upper end of the holder holder. .

[0011]

The artificial tooth root has a compressive strength because the contour of the anchor portion is a quadratic curve, does not sink, and has a notch formed in the tapered outer peripheral surface. Has excellent machinability. Since the length of the notch is longer than the interval between the notches, the small pieces of bone collected in the notch become a part of the new bone, so that they are firmly fixed.

[0012] If the cross section of the thread of the anchor portion is triangular, the screwing at the time of tapping is further facilitated 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 is easy to apply torque by attaching a tightening tool to that portion, and the portion is oval. If it is shaped, it will make good contact with its surroundings.

If the diameter of the neck portion is smaller than the base end of the anchor portion, the new bone is easily formed at the neck portion, and the fixation of the root is facilitated and firm.

If a crown holder having an elliptical outer periphery and a magnet keeper made of a magnetic material fitted therein are provided as a crown mounting holder, the mounting of the crown with the magnet can be performed. It becomes possible easily and it becomes easy to confirm the directionality of the keeper holder.

[0016]

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

One of the features of this artificial tooth root is that it is tapered toward the tip, and the profile of the longitudinal section of the anchor portion, that is, the longitudinal section of the outer peripheral surface except for the threads 3 bulges outward. This is a quadratic curve. The tapered shape enhances the self-cutting property in combination with the notch of the screw thread, and enhances the strength of the anchor portion by the contour being a quadratic curve, thereby reducing the compressive force applied to the tooth root. The resistance is increased, and the thread 3 and the screw 3 are prevented from sinking or immersing into the bone. It is preferable that the outer peripheral surface 1a of the anchor portion converges at the front end, which has an advantage that cutting properties at the front end are generated.

Another major feature of the present invention is that a series of notches 4 are formed in the thread 3 such that the length of the notches is greater than or equal to 5 the spacing between the notches, thereby improving the self-cutting properties. And the fixability has been significantly improved. The shape of the notch 4 does not need to be particularly limited, and is formed, for example, in an arc shape as shown in FIG.

Further, as shown in FIG. 3, the relationship between the notch 4 and the interval 5 between the notches is as follows:
Assuming that the length of the interval is c, 1 ≦ b / c is satisfied in order to satisfy both the machinability and the fixability, and preferably b / c
<3. In one example, the height of the thread is 0.4 mm,
b = 1.5 mm and c = 1.0 mm. Note that b / c
If the number is set to 3 or more, the meaning as a screw thread is lost.

By making the length of the notch 4 longer than the interval between the notches, a relatively large number of notches 4 are formed in the screw thread 3 and the contour of the anchor portion is tapered. In combination with the shape, the edge of each notch is involved in cutting, so that the self-cutting property is significantly improved. Also, after implantation, bone fragments generated by cutting enter into each notch 4, and these bone fragments combine with the new bone and play a role of fixing, so that the fixation of the root is strengthened. Increase detent. The bone fragments placed in the valleys between the threads 3 combine with the new bone to increase resistance to dislodgement and increase resistance to compression.

The cross section of the thread 3 itself is preferably triangular as shown in FIG. 1, which has the advantage of reducing the screwing resistance during tapping and improving the machinability. The pitch of the thread is set to an appropriate size depending on various conditions.

In the artificial tooth root of the present invention, as shown in FIGS. 1 and 2, a portion 2 of a neck portion 2 adjacent to an anchor portion 1 is provided.
The cross-section of a is non-circular, particularly preferably formed as an ellipse as shown, which facilitates the loading of torque during insertion. Furthermore, since there is no corner in the case of an elliptical shape, there is an advantage that the contact with the surrounding bone is good.

As shown in FIGS. 1 and 2, this artificial dental root preferably has a neck portion 2 having a circular cross section except for a portion adjacent to the anchor portion 1 and a proximal end 1b of the anchor portion. It is configured with a smaller diameter, thereby facilitating bone regeneration at the neck.

When the artificial tooth is to be implanted in the jaw bone, a hole having a diameter smaller than that of the artificial tooth is formed at a predetermined position of the jaw bone by a drill or a drill, and the tooth root is inserted there. 2a is gripped by a tool and inserted while applying torque. The artificial tooth root is inserted to a predetermined depth while cutting the jaw bone by its tapered shape and self-cutting property by the screw thread 3 and the notch 4, and is set at that position. The bone fragments generated during the cutting process enter between the threads 3 and into the notches 4 and merge into the new bone to fix the roots.

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

Therefore, as shown in FIGS. 5 and 6, the keeper holder 7 is provided with a screw 7a for engaging with the screw hole 6 at the lower part.
And an annular portion 7 having a circular inner periphery and an elliptical outer periphery at the top.
b and a screw hole 8 on the upper axis. The magnet keeper 9 has a screw 9a for engaging with the screw hole 8 at a lower portion and a disk portion 9b to be fitted into the annular portion 7b at an upper portion. Use of such a holder facilitates installation of the crown on the artificial dental root.

[0027]

As described above, in the artificial tooth root according to the present invention, the contour is tapered by a quadratic curve, and a series of notches are formed in the thread with a length longer 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 further appropriately fixed, particularly excellent in detent performance, and has high stability. .

Further, by making the cross section of the thread into a triangular shape, the screwing is further facilitated, and the self-cutting property is further improved.

Further, by making the section of the neck portion adjacent to the anchor portion non-circular, torque can be easily applied, and the root can be easily implanted.

By making the non-circular portion of the neck portion an elliptical shape, the torque can be easily applied, and the 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 is easily formed around the neck portion, and the fixation is strengthened.

Further, the crown mounting holder is made up of a key holder having an elliptical outer periphery and a magnet key made of a magnetic material.
By using the par, the crown can be easily and appropriately attached, and the direction can be easily confirmed.

[Brief description of the drawings]

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

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

FIG. 3 is a sectional view taken along line AA of FIG. 1;

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

FIG. 5 (a) and (b) are crown mounting holders.
3A and 3B are a vertical cross-sectional view and a plan view of a keeper holder that constitutes a part of FIG.

FIG. 6 (a) and (b) are crown mounting holders.
FIG. 9 is a side view and a plan view of a magnet keeper constituting another portion of FIG.

7 (a) and 7 (b) are side views each showing a conventional artificial tooth root.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anchor part 2 Neck part 3 Screw thread 4 Notch 5 Portion between notches 6 Screw hole 7 Key holder 8 Screw hole of key holder

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61C 8/00

Claims (6)

(57) [Claims] 1. An anchor part to be implanted in a jaw bone, and a screw hole provided on a base end of the anchor part and provided on the 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 its tip and has a thread on its outer peripheral surface. The longitudinal 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 are provided in the screw thread such that the length of the notches is equal to or greater than the distance between the notches. An artificial tooth root, characterized in that: 2. The artificial tooth root according to claim 1, wherein the cross section of the thread is triangular. 3. A cross section of the neck portion adjacent to the anchor portion has a non-circular cross section.
An artificial tooth root according to the item. 4. The dental implant according to claim 3, wherein the non-circular shape is an elliptical shape. 5. The neck according to claim 1, wherein a portion of the neck portion other than a portion adjacent to the anchor portion has a circular cross section and a diameter smaller than a base end of the anchor portion. Artificial roots. 6. Further, as a crown mounting holder, a lower part has a screw engaging with the screw hole of the neck part, and an upper part has a screw hole in the center, and the inner periphery is circular and the outer periphery is elliptical. Key
And a lower part having a screw engaged with a screw hole of the keeper holder, and an upper part having the retainer holder.
2. The artificial tooth root according to claim 1, further comprising a circular magnetic material that is fitted into the inner periphery of the upper end.