JP2002253580A - Artificial tooth root - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a technique and to prevent the bacterial infection by allowing the self-tapping of the whole artificial tooth root including a major diameter part to a bone. SOLUTION: This artificial tooth root 1 comprises a cylindrical part 3 having a self tap type screw 5 formed on the circumference, and a conical part 2 continued to the cylindrical part 3 and extended as it leaves the cylindrical part 3, and having a self-tap type screw formed on the circumference. A screw 4 of the conical part 2 is formed so that the screw thread height d1 of the screw 4 is gradually reduced toward the direction leaving from the cylindrical part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial tooth root, and more particularly to an artificial tooth root having a function of enabling aesthetic treatment or a function of immediate load.

[0002]

2. Description of the Related Art Conventionally, an artificial root having a small-diameter portion and a large-diameter portion embedded in bone has been used.

[0003] This artificial tooth root has a small diameter portion in the cancellous bone portion on the back side of the jaw bone and a large diameter portion in the cortical bone side near the gingiva. In addition to being able to reconstruct the tooth shape with a simple line, there is an advantage that the direction in which the artificial tooth root is to be implanted can be selected and the direction can be changed within a limited bone mass. In addition,
If the end of the artificial tooth root and the artificial crown are not connected with a smooth line, a gap will be formed between the jaw bone and the artificial crown (gingival papilla) because the gum does not enter between them. This is not aesthetically pleasing.

[0004] Such artificial dental roots include the following types.

(1) An artificial tooth root having a large diameter portion whose diameter gradually increases as the distance from the small diameter portion increases, and a non-self-tapping screw is formed on the outer periphery of the small diameter portion and the large diameter portion.

(2) A conical portion as a large-diameter portion, which is continuous with the cylindrical portion as the small-diameter portion and expands as the distance from the cylindrical portion increases, and is provided on the outer periphery of the cylindrical portion. Is an artificial tooth with a non-self-tapping screw.

(3) A conical portion as a large-diameter portion, which is continuous with the cylindrical portion as the small-diameter portion and expands away from the cylindrical portion, and self-tapping on the cylindrical portion. An artificial dental tooth having the above screw, and having micro unevenness formed on the conical part in the hope that bone is formed in the gap.

[0008]

However, among the above-mentioned conventional artificial tooth roots, (1) and (2) each employ a non-self-tapping screw, and a screw groove is formed in a bone by a tapping tool. If it is necessary and if the formed screw hole is not precise, a gap is formed, and a fixing force cannot be obtained or bacterial infection may occur, so that a high skill is required for a dentist who is an operator.

On the other hand, in the case of the artificial root of (3), it was not necessary to form a screw hole in the bone by drilling, but a gap was formed between the micro unevenness of the conical portion and the bone in the initial stage of implantation. However, there was a risk of bacterial infection until bone was formed between the irregularities. Peri-implantitis is induced by the bacterial infection, and the artificial root must be removed.

In view of these problems of the prior art, an object of the present invention is to enable self-tapping to a bone by the entire artificial tooth root including a large diameter portion, to simplify a surgical procedure, and to prevent bacterial infection. I do.

[0011]

In order to solve the above-mentioned problems, the artificial tooth root according to claim 1 has a cylindrical portion having a self-tapping screw formed on the outer periphery thereof, and a cylindrical portion continuous with the cylindrical portion. It has a conical portion with a cell tap type screw formed on its outer periphery, and the height of the screw thread gradually decreases in the direction away from the cylindrical portion. It is characterized by doing.

According to this structure, the height of the screw ridge gradually decreases in the direction in which the screw in the conical portion moves away from the cylindrical portion. First, the first screw portion close to the cylindrical portion first begins to cut bone alone. At this time, since the torque for rotating the artificial tooth root can be concentrated on the screw portion, the screw can be cut with a small force. Then, the screw sequentially cuts the bone from the portion closest to the cylindrical portion to the farthest portion while rotating the artificial root about one round. As described above, the conical portion is also fixed with the screw by self-tapping, so that the artificial tooth root can be firmly fixed to the bone, and since there is almost no gap between the bone and the artificial tooth root, the possibility of bacterial infection is very high. Small. Furthermore, since the formation of the screw groove by the tapping tool is not required, the operation method is simple.

According to a second aspect of the present invention, the minimum screw thread height in the conical portion is 0.1 mm or less.

With regard to the conical portion, while the thread is cut by about one rotation, a groove as a trace of a thread cut off at a portion of the conical portion farthest from the cylindrical portion remains on the bone side. According to the configuration of claim 2, since the height of the screw thread is very low, the groove formed as a trace of the screw thread by tapping is very shallow, and as a result, the gap between the bone and the artificial tooth root at this portion is reduced. There is almost no gap.

If the gap between the bone and the artificial tooth in the groove as the trace of the screw thread is large, a gap that cannot be ignored exists at the bone edge, and the bone tissue surrounding the artificial tooth causes bone resorption. Sometimes. Then, the possibility of bacterial infection is increased by the bone resorption.

According to the second aspect of the present invention, there is almost no gap between the bone and the artificial root at the edge of the bone.
There is no fear of such bacterial infection.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 show an artificial tooth root of this embodiment. In these figures, reference numeral 1 denotes an artificial tooth root, 2 denotes a conical part, 3 denotes a cylindrical part, 4 denotes a multi-threaded screw, and 5 denotes a single tooth. It is a screw.

The artificial tooth root 1 has a cylindrical portion 3 on the distal end side in which a self-tapping single screw 5 is formed on the outer periphery, and as the cylindrical portion 3 continues from the cylindrical portion 3 and moves away from the cylindrical portion 3 ( 1 has a conical portion 2 on the rear end side on which the cell tap type multi-threaded screw 4 is formed on the outer periphery. Further, the screw of the conical portion 2 extends from the minimum diameter portion 2a of the conical portion 2 to the maximum diameter portion 2a.
The thread height d1 gradually decreases toward b, that is, in a direction away from the cylindrical portion 3.

The material of the artificial tooth root 1 is Ti-6
A biologically safe metal material such as an Al-4V alloy or pure titanium is used. The surface is preferably subjected to a treatment such as anodic oxidation, hydroxyapatite spraying, sand blasting, or titanium spraying to increase the affinity between the surface and the bone.

The cylindrical portion 2 has a dome shape at one end (the lower side in FIG. 1). The single screw 5 formed on the outer periphery has a screw thread height d2 set to be larger than the screw thread height d1 of the multi-thread screw 4 in the conical portion 3.

The conical portion 2 has the multi-threaded screw 4 as described above, and its pitch is substantially the same as the single-threaded screw 5 of the cylindrical strip 3. That is, when the multi-thread screw 4 is an n-thread screw (n is an integer), the distance w1 from the one screw thread to the n-th screw thread is adjacent to the single screw thread 5 in the conical portion 2. It is almost equal to the distance w2 between the screw threads.

Also, as shown in FIG.
Is, for example, the flare angle A1 of the screw bottom portion is 25 ° and the flare angle A of the screw top portion is
A1> A2 such that 2 is 20 °. That is, the screw thread height d1 (see FIG. 1) of the polyhedral screw 4 gradually decreases from the minimum diameter portion 2a of the conical portion 2 to the maximum diameter portion 2b.

The difference between the flare angles is expressed by A1
-A2 is preferably 1 ° to 6 °. When the difference A1-A2 of the flare angles is less than 1 °, the screw thread formed on the bone side becomes fine, and there is a possibility that the effect of improving the fixing force in the cortical bone portion may not be exhibited. In such a case, the height of the screw thread becomes unnecessarily high, and as a result, there is a fear that a large resistance is generated during self-tapping.

In the present embodiment, the multi-thread screw 4 is
As will be described later, the minimum thread height d3 of the maximum diameter portion 2b in the conical ridge portion 2 is set to 0.1 mm or less in order to minimize the possibility of bacterial infection.

FIG. 3 and FIG. 4 are explanatory views showing an installation mode of the artificial tooth root 1.

In these figures, the thin line indicated by the symbol B indicates the jaw bone.

As shown in FIGS. 3 and 4, the cylindrical portion 2 is first inserted into the artificial root insertion hole H formed in the jaw bone B in advance with a substantially cylindrical inner portion and a conical portion near the opening. I will do it. Immediately after the tip starts to enter the substantially cylindrical portion of the artificial tooth insertion hole H, the first thread of the single screw 5 in the cylindrical portion 3 of the artificial tooth root 1 hits the jaw bone B. From there,
As you advance the artificial tooth 1 in the depth direction while rotating,
By the self-tapping of the single screw 5, the cylindrical portion 3 of the artificial tooth root 1 is screwed into the jaw bone B in order from the tip while cutting the jaw bone wall.

When this screwing is advanced, when the tip of the cylindrical portion 3 of the artificial tooth root 1 almost reaches the hole bottom of the artificial tooth root insertion hole H, the conical part 3 becomes the cone of the artificial tooth root insertion hole H. Start to hit the bone wall in the part. FIG.
Indicates the state. At this time, since the thread height d1 of the multi-threaded screw 4 gradually decreases from the minimum diameter portion 2a to the maximum diameter portion 2b of the conical portion 2 as described above, the first screw portion of the minimum diameter portion 2a in the conical portion 2 4b
However, first, the jaw bone B begins to be scraped alone. Therefore, since the torque for rotating the artificial tooth root 1 can be concentrated on the screw portion 4b, the bone can be screwed with a small force.

While the artificial tooth is being rotated about one turn, the multi-thread screw 4 is sequentially turned from the minimum diameter portion 2a of the conical portion 2 to the maximum diameter portion 2b (from bottom to top in FIGS. 3 and 4). Sharp bones. Then, the last screw portion 4c of the largest diameter portion 2b of the conical portion 2 is engaged with the bone, and the insertion is completed when the bone is further advanced. FIG. 4 shows this state.

As described above, in the artificial tooth root 1, since the pitch of the multi-threaded screw 4 of the conical portion 2 and the single-threaded screw 5 of the cylindrical portion 3 are substantially the same, the screw is screwed into the bone. Is performed regularly. As a result, the multi-thread screw 4 does not destroy the surrounding bone.

As described above, according to the artificial tooth root 1, the conical portion 2 is also screw-fixed by self-tapping.
The artificial tooth root 1 can be firmly fixed to the jaw bone B, and since there is almost no gap between the jaw bone B and the screw of the artificial tooth root 1, the possibility of bacterial infection is very small. Furthermore, since the formation of the screw groove by the tapping tool is not required, the operation method is simple.

Further, in the artificial tooth root 1, since the screw of the conical portion 2 is a multi-thread screw 4, the fixing force of the conical portion 2 screwed to the hard cortical bone can be increased. The fixing force of the entire artificial tooth root 1 to the jaw bone B can be dramatically increased.

Further, as described above, the artificial tooth root 1 has the minimum thread crest height d of the multi-threaded screw 4 in the conical portion 2.
Since 3 is 0.1 mm or less, almost no gap is formed between the bone and the artificial tooth root 1 formed as a trace of the screw thread at the bone edge (indicated by reference numeral B1 in FIG. 4) due to tapping. Therefore, there is no possibility that the bone tissue surrounding the artificial tooth root 1 causes bone resorption to cause bacterial infection.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it goes without saying that the present invention can take any form without departing from the object of the invention.

[0036]

As described above, the artificial tooth root of the present invention has a cylindrical portion having a self-tapping type screw formed on the outer periphery, and has a divergent shape that is continuous with the cylindrical portion and becomes more distant from the cylindrical portion. And a conical portion having a cell tap type screw formed on the outer periphery thereof. The screw of the conical portion has
By configuring the screw thread height to gradually decrease in the direction away from the cylindrical portion, when the conical portion hits the wall of a predetermined hole formed in the jaw bone in advance, the screw portion close to the cylindrical portion, First, start cutting bones alone. At this time, since the torque for rotating the artificial tooth root can be concentrated on the screw portion, the screw can be cut with a small force. Then, the screw starts to cut bone in order from the portion closest to the cylindrical portion to the farthest portion while rotating the artificial root about one round. As described above, the conical portion is also fixed with the screw by self-tapping, so that the artificial tooth root can be firmly fixed to the bone, and since there is almost no gap between the bone and the artificial tooth root, the possibility of bacterial infection is very high. Small. Furthermore, since the formation of the screw groove by the tapping tool is not required, the operation method is simple.

In the artificial tooth root, when the minimum screw thread height in the conical portion is 0.1 mm or less, the screw thread height at the portion farthest from the cylindrical portion is very low. The gap between the bone and the artificial root as a trace of the mountain is very small. Therefore, there is no fear of bacterial infection.

[Brief description of the drawings]

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

FIG. 2 is a partially enlarged view of the artificial root of FIG. 1;

FIG. 3 is a side view showing an installation mode of the artificial tooth root of FIG.

FIG. 4 is a side view showing an installation mode of the artificial tooth root of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Artificial root 2 Conical part 2a Minimum diameter part 2b Maximum diameter part 3 Cylindrical part 4 Multi-thread screw 5 Single-thread screw d1 Thread height d2 Thread height w1 Width w2 Width B Jaw bone H Artificial root insertion hole

Claims (2)

[Claims] 1. A cylindrical portion having a self-tapping screw formed on the outer periphery thereof, the cylindrical portion being continuous with the cylindrical portion and diverging away from the cylindrical portion. An artificial tooth root, the height of which is gradually reduced in a direction away from the cylindrical part. 2. The artificial tooth root according to claim 1, wherein the minimum screw thread height in the conical portion is 0.1 mm or less.