JPH0880305A - Formation of abutment reinforcement and jig for abutment reinforcement used therein - Google Patents

Abstract

PURPOSE: To form an abutment reinforcement by a simple method by which sufficient reinforcement of the tooth substance is obtd., the impartation of excessive stresses on a dental root surface is averted and the possibility of a dental fracture and post dislodgment is eliminated. CONSTITUTION: A cavity 11 provided with an undercut 12 is formed (a) at the abutment tooth T. A trial pin 33 screwed with a disk-shaped member 31 having a closed notch is inserted into this cavity 11 and thereafter, hot air is blown to open (b) the notch of this disk-shaped member 31. After the trial pin 33 is removed, a resin 34 is packed into the notch and is cured (c). A post body 32 is screwed (d) to the disk-shaped member 31, by which the abutment reinforcement is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an abutment structure to make up for a tooth defect in a crown portion, and a jig used for carrying out the method for forming an abutment structure. .

[0002]

2. Description of the Related Art Most of teeth having a missing tooth structure or requiring pulp treatment are very fragile and easily chipped, and such a tooth is simply filled with a prosthesis. If it does, it is expected that it will come off easily. Therefore, it is necessary to reinforce the dentin as well as to reinforce the ground when constructing a building on a poor land. This is the abutment construction for teeth. In the abutment construction, if the abutment tooth to which the artificial crown is attached has a large defect and it seems that the retaining force of the superstructure is insufficient in that state, or the tooth implantation direction is not correct. It is also formed in some cases.

The abutment construction is divided into two parts, a post located in the root canal part and a core located in the crown part, and the building method is a metal material typified by a ready-made metal post. It is classified into a building by, a building by a molding and filling material such as a resin, and a construction by combining a metal material and a molding and filling material. And according to the purpose of the abutment construction, such as strengthening the tooth structure, strengthening the holding power, and improving the dimensional accuracy,
An optimum method is selected from these building methods and executed in view of the tooth deficiency state and the shape of the abutment tooth. Also, there are two types of posts, prefabricated posts and cast posts, whichever type is used,
Conventionally, dental cement is used to bond and maintain the inner surface of the root and the post.

[0004]

However, due to the stress of the meshing force after the formation of the abutment structure, the teeth after the formation of the abutment structure, especially the root canal, is broken, and the formed abutment structure is dropped. Occasionally, there are many cases in which measures such as rebuilding the abutment structure must be taken. In the conventional abutment construction, the adhesive force of the dental cement is lost due to the vibration due to the meshing force and the exudate from the tooth tube, and a gap is created between the inner surface of the tooth root and the post, causing the post to fall off or break the root. It may be a cause. In addition, when the disease on the root side reoccurs, it is extremely difficult to remove the post during retreatment of the root because the inner surface of the root and the post are firmly adhered to each other by dental cement. Sometimes he broke and had to extract his teeth. Therefore, development of a new abutment construction method different from the existing methods is desired.

The present invention has been made in view of such circumstances, and it is possible to obtain sufficient strengthening of the dentin, no excessive stress is applied to the tooth root surface, and there is no fear of tooth root fracture. It is possible to provide a novel abutment construction method and a jig for abutment construction that can be used to form an abutment construction by a simple technique without fear of falling off and easily remove the post when retreating a tooth root. To aim.

[0006]

A method for forming an abutment structure according to claim 1 of the present application is a method for forming an abutment structure on an abutment tooth, wherein a cavity is formed from the surface of the abutment tooth, and the cavity is formed. An undercut is formed on the inner peripheral surface of the formed abutment tooth, and a metal member surrounding the softened thermoplastic resin on the outer peripheral surface thereof is inserted into the cavity of the abutment tooth to cool the thermoplastic resin. And then cured to form an abutment structure.

The jig for abutment construction according to claim 2 of the present application is
In an abutment building jig used when forming an abutment structure on an abutment tooth, a first member made of metal and a second member made of a thermoplastic resin joined to an outer peripheral surface of the first member. It is characterized by including.

The method of forming an abutment structure according to claim 3 of the present application is a method of forming an abutment structure on an abutment tooth, wherein a cavity is formed from the surface of the abutment tooth, and the abutment having the cavity is formed. An undercut is formed on the inner peripheral surface of the tooth, so that the disk-shaped member made of a shape memory alloy screwed onto the outer peripheral surface fits the undercut, a metal member is inserted into the cavity, and the disk-shaped member It is characterized in that an abutment structure is formed by utilizing shape memory and / or superelasticity.

The abutment building jig according to claim 4 of the present application is
In an abutment building jig used when forming an abutment building on an abutment tooth, a first member made of metal and a second member made of a shape memory alloy screwed onto an outer peripheral surface of the first member. And is provided.

[0010]

In the abutment construction formed according to the present invention, the softened thermoplastic resin surrounding the outer peripheral surface of the metal member enters the undercut formed on the inner peripheral surface of the tooth root and is hardened. The inner peripheral surface and the thermoplastic resin are intimately bonded to each other, so that there is no gap between the post and the inner peripheral surface of the tooth root, and a strong bond between them can be obtained without the intervention of dental cement.
Therefore, the post does not fall off, and the root is not broken. Further, the elasticity of the thermoplastic resin can disperse the meshing force and prevent the fracture of the tooth root. Further, when the disease of the root reoccurs, the post in the root can be easily removed by heating and softening the hardened thermoplastic resin, and the root can be re-treated.

In another abutment construction according to the present invention, since the disk-shaped member made of a shape memory alloy is provided in the undercut formed on the inner peripheral surface of the tooth root, the shape-memory property of the disk-shaped member and Depending on the superelasticity, the inner peripheral surface of the tooth root and the disk-shaped member are intimately joined to each other, so that the metal member (post body) screwed to the disk-shaped member and the tooth root are firmly joined. Therefore, the post does not fall off, and the root is not broken. In addition, when the disease of the tooth root recurs, the post body in the tooth root can be easily removed, and the tooth root can be retreated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments.

(First Embodiment) First, the members used in the first embodiment of the method for forming and forming an abutment of the present invention will be described. FIG. 1 is a perspective view showing a titanium alloy member 1 made of a titanium alloy as a metal member, and a plastic member 2 made of a thermoplastic resin in a solidified state surrounding a screw portion 1a of the titanium alloy member 1 described later in a sheath shape. Is.

The titanium alloy member 1, as shown in FIG.
A small diameter cylindrical threaded portion 1a, a large diameter cylindrical large diameter portion 1b connected to the threaded portion 1a, and a solid taper portion 1c connected to the large diameter portion 1b and reduced in diameter toward the end. It consists of A screw 1d is formed on the outer peripheral surface of the threaded portion 1a over substantially the entire area in the longitudinal direction. As shown in FIG. 1, the plastic member 2 has a bottomed cylindrical shape that is slightly longer than the threaded portion 1a of the titanium alloy member 1. Since this plastic member 2 is formed by surrounding the outer peripheral surface of the threaded portion 1a of the titanium alloy member 1 with a softened thermoplastic resin and then cooling it, the screw 2a is cut on the inner peripheral surface thereof. Therefore, the length of the screw 2a is the same as the length of the screw 1d of the titanium alloy member 1. Therefore, screw 1d and screw
The titanium alloy member 1 and the plastic member 2 are mechanically coupled by screwing with the 2a. The threaded portion 1a of the titanium alloy member 1 and the plastic member 2 constitute a post of abutment construction, and the large diameter portion 1b and the tapered portion 1c of the titanium alloy member 1 constitute a core.

Next, a method of forming an abutment structure on the abutment tooth of the first embodiment will be described. 2 and 3 are a cross-sectional view and a perspective view showing the procedure of the method of forming the abutment. In the figure, T is an abutment tooth.

First, a cavity 11 slightly longer than the threaded portion 1a of the titanium alloy member 1 is formed in the abutment tooth T from the root surface using a high-speed rotating drill (FIG. 2 (a)). Then, after forming an undercut 12 on a part of the inner circumferential surface of the abutment tooth T in which the cavity 11 is formed, over the entire circumferential direction, the tooth root surface is polished to be smooth and the root canal is dried (Fig. Two
(B)). At this time, root canal treatment is performed if necessary. Next, a post made by heating and softening the plastic member 2 fitted to the outer periphery of the screw portion 1a (in other words, the titanium alloy member 1 surrounded by the thermoplastic resin 21 in which the outer peripheral surface of the screw portion 1a is softened). Insert into cavity 11 (Fig. 2
(C), FIG. 3). At this time, the thermoplastic resin 21 is
The undercut 12 is filled between the threaded portion 1a of the titanium alloy member 1 and the inner surface of the tooth root without any gap. The inserted post is cooled to cure the thermoplastic resin 21 (FIG. 2 (d)). Due to the hardening of the thermoplastic resin 21, the titanium alloy member 1 and the solidified thermoplastic resin 21 are joined in a screwed state, and the presence of the solidified thermoplastic resin 21 in the undercut 12 causes the inner surface of the tooth root to be thermoplastic. A close bond with the resin 21 is obtained. At this time, the large diameter part of the titanium alloy member 1
The lower end surface of 1b comes into contact with the root surface of the abutment tooth T, but since the root surface is made smooth by polishing, the contact between them is good and the stress is evenly distributed without being concentrated at one location. Dispersed in.

As described above, the formation of the abutment structure is completed on the abutment tooth T. Then, clinically, titanium alloy member 1
After cutting the large-diameter portion 1b and the taper portion 1c into a predetermined shape, an artificial dental crown is put on them.

In the abutment construction thus formed, the inner surface of the tooth root and the post are firmly joined by the hardened thermoplastic resin 21, and therefore the abutment construction (post) falls off due to the joining force. There is no fear, and it is possible to realize the maintenance of mechanical abutment construction that is strong in tooth quality. Further, since the meshing force (stress) is dispersed by the elasticity of the thermoplastic resin 21, the abutment tooth T is unlikely to break. In addition, since the above-mentioned forming method does not require any special technique,
Abutment construction can be easily formed.

Next, a description will be given of the treatment when the disease recurs in the tooth root formed with the abutment construction in the first embodiment. In such a case, first, the artificial crown covering the post is removed, and then the post is heated to soften the thermoplastic resin 21 to remove the post. Then, the exposed tooth root is re-treated. In this way, even after forming the abutment structure, the post can be easily removed to perform retreatment of the tooth root.

By the way, the abutment teeth forming the abutment construction are not always upright, but may be inclined. With respect to the inclined abutment tooth, the root surface and the core are not in close contact with each other over the entire area, so that stress may be concentrated. Therefore, in such a case,
An application is also possible in which a disc-shaped metal member is fitted on the upper part of the post to disperse stress.

The thermoplastic resin used in the present example preferably contains a rubber substance so as to enhance elasticity, and the drawback of the dental cement that it deteriorates and becomes brittle can be solved. Further, a screw may be formed on the inner surface of the tooth root. Further, although the screw is formed on the metal portion of the post, other means other than the screw may be applied as long as the screw can be joined to the hardened thermoplastic resin.

(Second Embodiment) The second embodiment of the present invention will be described below. First, the members used in the second embodiment, that is, the disk-shaped member, the post body, and the trial pin will be described. FIG. 4 is a plan view of the disc-shaped member 31. The disk-shaped member 31 is made of a Ni—Ti (nickel-titanium) alloy, which is a shape memory alloy. FIG. 4A shows the shape after the shape is subjected to a memory treatment, and FIG. The shape after cooling after the memory processing is shown. That is, FIG. 4A shows the shape of the parent phase (austenite phase), and FIG.
Indicates the shape of the martensite phase state.

The disk-shaped member 31 is in the form of a flat disk having a hole 31a formed in the center thereof, and a screw 31b is cut on the entire inner peripheral surface thereof in the thickness direction. Further, four notches 31c concentric with the holes 31a are formed at equal pitches. In the martensite phase state, the notches 31c are barely opened as shown in FIG. 4 (b), but in the mother phase state, the notches 31c are slightly opened as shown in FIG. 4 (a).

FIG. 5 is a perspective view of the post body 32 and the trial pin 33. The post body 32 is made of a titanium alloy, and is composed of a small-diameter cylindrical small-diameter portion 32a and a large-diameter cylindrical large-diameter portion 32b integrally connected to the small-diameter portion 32a.
A screw 32c is cut on a part of the peripheral surface on the side of the large diameter portion 32b. On the other hand, the trial pin 33 is made of a titanium alloy and has a cylindrical shape with an equal diameter as a whole, and a screw 33a is cut on a part of the circumferential surface in the longitudinal direction.

Next, a method of forming an abutment structure on the abutment tooth of the second embodiment will be described. FIG. 6 is a cross-sectional view showing the procedure of this abutment building forming method. In the figure, T is an abutment tooth.

First, as in the first embodiment, a post main body 32 and a trial pin 33 having substantially the same diameter as the large diameter portion 32b of the post main body 32 are formed from the root surface of the abutment tooth T using a high-speed rotating drill. After forming the cavity 11 which is slightly longer, an undercut 12 is formed on a part of the inner peripheral surface of the abutment tooth T in which the cavity 11 is formed over the entire circumferential direction thereof, and the root surface is polished to be smooth. The root canal is dried (FIG. 6 (a)). At this time, root canal treatment is performed if necessary. Next, a trial pin 33 screwed with the disk-shaped member 31 with the notch 31c closed.
Is inserted into the cavity 11 of the abutment tooth T so that the disc-shaped member 31 is positioned in the undercut 12, and then hot air is blown through the gap between the trial pin 33 and the inner surface of the root to form the disc-shaped member.
The 31 is restored to the matrix state shown in FIG. 4 (a) in which the notch 31c is opened (FIG. 6 (b)). After that, the trial pin 33 is removed from the disk-shaped member 31, and the resin 34 is filled in the cavity 11 including the undercut 12 and hardened (FIG. 6C). Finally,
The post main body 32 is screwed into the disc-shaped member 31 to complete the formation of the abutment structure on the abutment tooth T (FIG. 6D). Then, clinically, an artificial crown is formed so as to cover the surface of the abutment tooth T and the surface of the post body 32.

In the abutment construction thus formed, the inner surface of the tooth root and the post body 32 are formed by the disk-shaped member 31 that is cut into the undercut 12 with the notch 31c opened.
Since and are firmly joined, by the joining force,
There is no risk of the abutment building (post) falling off, and it is possible to maintain the mechanical abutment building that has tooth strength and strength. Further, since the meshing force (stress) is dispersed by the elasticity of the resin 34, the abutment tooth T is unlikely to break. In addition, since the above-mentioned forming method does not require any special technique,
Abutment construction can be easily formed.

A modified example of the second embodiment will be described below. Although the shape memory property is used in the above-described example, the superelasticity of the shape memory alloy is used in the following examples. By changing the composition ratio of Ni and Ti in the Ni-Ti alloy to the above-mentioned example, the disk-shaped member 31 having superelasticity at room temperature is used. Then, by utilizing this superelastic property, the inner surface of the tooth root and the post body
Get a strong bond with 32. The disk-shaped member 31 in a low temperature state that does not exhibit superelasticity is positioned in the undercut 12 and returned to room temperature, so that the disk-shaped member 31 exhibits superelasticity. Alternatively, after the disc-shaped member 31 whose superelasticity is suppressed by the wire or the pin is positioned in the undercut 12 at room temperature, the wire is cut or the pin is removed to exert the superelasticity of the disc-shaped member 31. Let The basic abutment construction process is the same as in the above example.

Next, a description will be given of the treatment when the disease recurs in the tooth root having the abutment construction as in the second embodiment. In such a case, first, after removing the covered artificial crown, the post body 32 is removed, the resin 34 is removed from the central hole 31a of the disk-shaped member 31, and the re-treatment of the root exposed through the hole 31a is performed. Do. In this way, even after forming the abutment structure, the post can be easily removed to perform retreatment of the tooth root.

In each of the above-mentioned embodiments, the undercut is formed over the entire circumference at one location on the inner surface of the tooth root, but it may be formed at a plurality of locations or in a partial area in the circumferential direction. Further, in each of the above-described embodiments, the titanium alloy was used as the material of the metal member in the post, but this is an example, and it goes without saying that other metals or alloys such as stainless steel may be used. . Furthermore, the number and shape of each member,
It is needless to say that the size, shape, and size of these are to be determined according to the type of the abutment tooth T (front tooth, canine tooth, molar) and the condition of tooth loss, as examples of dimensions such as diameter and length are examples. .

[0031]

As described above, according to the present invention, since a strong bond can be obtained between the post and the inner surface of the root without the intervention of dental cement, the post does not fall off and the root is not broken. It can be prevented. Furthermore, if the root disease reoccurs, the post can be easily removed and re-treated.
As described above, according to the present invention, it is possible to strengthen the tooth structure, and easily form the abutment structure without breaking the abutment tooth and dropping the abutment tooth itself without performing a special technical treatment. It becomes possible and contributes to the progress of dental treatment, and has excellent effects.

[Brief description of drawings]

FIG. 1 is a perspective view of an abutment building jig according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the procedure of an abutment building forming method according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a procedure of an abutment building forming method according to the first embodiment of the present invention.

FIG. 4 is a plan view of an abutment building jig (disk member) according to a second embodiment of the present invention.

FIG. 5 is a perspective view of an abutment building jig (post body, trial pin) according to the second embodiment of the present invention.

FIG. 6 is a sectional view showing a procedure of an abutment building forming method according to the second embodiment of the present invention.

[Explanation of symbols]

 1 Titanium alloy member 2 Plastic member 11 Cavity 12 Undercut 21 Thermoplastic resin 31 Disc member 31b, 32c, 33a Screw 31c Notch 32 Post body 33 Trial pin T Abutment tooth

Claims (4)

[Claims] 1. A method of forming an abutment structure on an abutment tooth, wherein a cavity is formed from a surface of the abutment tooth, and an undercut is formed on an inner peripheral surface of the abutment tooth in which the cavity is formed, An abutment characterized in that a metal member surrounding a softened thermoplastic resin on its outer peripheral surface is inserted into the cavity of the abutment tooth, and the thermoplastic resin is cooled and hardened to form an abutment structure. Construction method. 2. A jig for abutment construction used when forming an abutment construction on an abutment tooth, comprising a first member made of metal and a thermoplastic resin joined to an outer peripheral surface of the first member. A jig for abutment construction, comprising: 3. A method of forming an abutment structure on an abutment tooth, wherein a cavity is formed from a surface of the abutment tooth, and an undercut is formed on an inner peripheral surface of the abutment tooth in which the cavity is formed, A metal member is inserted into the cavity so that the disk-shaped member made of a shape memory alloy screwed onto the outer peripheral surface fits the undercut, and the shape-memory property and / or superelasticity of the disk-shaped member is utilized. A method of forming an abutment, characterized by forming an abutment. 4. A jig for building an abutment used when forming an abutment building on an abutment tooth, wherein a metal first member and a shape memory alloy screwed onto an outer peripheral surface of the first member. An abutment building jig, comprising: a second member made of steel.