JPH0650423B2 - Method for manufacturing tooth model with pulp cavity - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a tooth model having a pulp cavity for use in practice of dental treatment.

(Prior Art) Conventionally, a clinician often performed a mechanical operation without paying much attention to the morphology of the pulp cavity when performing a pulp cutting method or a root canal treatment such as pulp extraction. . However, this operation is often a major cause of treatment failure, and the more carefully the root canal is treated, the deeper the realization of the complexity of the root canal and the difficulty of treatment will be. A thorough understanding of the anatomical complexity of some teeth, especially pulp, is the best basic idea of successful endodontic therapy.

It is needless to say that the natural teeth in perfect condition are optimal for the teeth to be used in the above-mentioned dental practice, but in the current situation where the absolute number of perfect teeth is insufficient, it is inevitable that artificial teeth will be used. There is only a method for conducting training training using a tooth model by MU., And therefore various artificial teeth have been developed and used.

For example, although there is a tooth model having a pulp cavity as shown in FIGS. 6 and 7 of the accompanying drawings, the tooth model of FIG.
It is also disclosed in Japanese Patent Publication No. 56-24278, for example, after casting a metal having the shape of a pulp cavity and forming a dentin portion b having the metal pulp a therein, an open portion c is formed.
It is manufactured by the method of infiltrating aqua regia from the solution and dissolving the metal pulp to form the enamel part.However, since the pulp horn of the pulp cavity penetrates the boundary line between enamel and dentin, It may be useful as a filling material, but it could not be used for practicing root canal treatment.

Root canal treatment in endodontics is based on the setting of the outline of the tooth,
After removal of enamel and dentin (formation of cavernous cavity), penetration of the medullary canal, removal of the canopy, removal of the contents of the medullary chamber, cleaning of the medullary canal, and confirmation of the root canal opening, Measurements, root canal dilation, and root canal formation are required.

The example shown in FIG. 7 is disclosed in Japanese Patent Laid-Open No. 59-186551.
Although it is also disclosed in Japanese Patent Publication, the pulp cavity is opened at the boundary line d between the enamel and the dentin and the root apex e. For example, a metal wire is used to change the shape of the pulp cavity. It is manufactured by a method of forming the dentin part b having the metal wire inside, forming the enamel part f after removing the metal wire from the open part.

However, unlike the structure of a natural tooth, such a tooth model has a medullary horn reaching the boundary line between enamel and dentin, and thus, similar to the above, a root canal treatment that requires advanced and delicate treatment techniques. It could not be used for practical training.

Furthermore, Japanese Utility Model Publication No. 56-28620 discloses a tooth model having a structure similar to a natural tooth as an artificial tooth for learning the work of root canal treatment. However, such a tooth model is not integrally molded. As it cannot be manufactured, it is manufactured by dividing it into two or more pieces, and then bonding and integrating them. In this way, the model with the adhesive surface at the center of the tooth is similar to natural teeth. It was difficult to carry out the practical training.

(Problems to be Solved by the Invention) The pulp cavity of a natural tooth exists in the dentin, and its shape is basically close to a reduced view of the outer shape of the tooth.
Like the respective shapes, the pulp cavity has its own characteristics. In addition, the apical portion opens as an apical hole, and is the only opening through which the vascular nerve bundle enters and exits the pulp cavity. That is, the pulp cavity of a natural tooth has a structure in which only the root apex is opened and does not penetrate to the boundary line between enamel and dentin, and the treatment requires careful attention to the internal structure of the tooth. Need to be treated.

However, as described above, there is no conventional tooth model that can be treated like a natural tooth.

The present invention provides a method for manufacturing an undivided tooth model that accurately represents the internal structure of a natural tooth, and thereby provides trainees with accurate knowledge when studying, training and practicing advanced medical technology. The purpose is.

(Means for Solving Problems) In the present invention, a wax pulp model is formed by a negative shape of the pulp cavity, and the pulp model is prepared without contact of the medullary horn with the enamel portion. With the cusps not covered by the dentin,
After encapsulating it in the negative mold of the tooth together with the enamel part that was previously molded with synthetic resin, inject the synthetic resin into the negative mold of this tooth and cure it to integrate it with the enamel part and the pulp cavity model. In this state, the dentin part is molded, the integrated molded product is taken out, heated, and the wax of the dental pulp model is melted and ejected from the root apex under reduced pressure, so that only the root apex is opened. It was possible to get a model.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

FIG. 1 is a front view of a tooth model manufactured by the manufacturing method of the present invention, and FIG. 2 is a vertical sectional view of the tooth model of FIG. 1, in which A is a tooth model, 1 is an enamel portion, and 2 is ivory. Dental part, 3 is a borderline between enamel and dentin part, 4 is pulp cavity, and 5 is apical part.

3 to 5 are cross-sectional views showing a manufacturing process of the manufacturing method of the present invention, FIG. 3 is a cross-sectional view of a negative mold for molding a wax pulp model, and FIG. Shown is a molded wax pulp model, in which 6 and 6'are silicone negative molds, 7 is a wax injection port, 8 is a guide, 9 is a dividing surface portion,
Reference numerals 10 respectively show pulp pulp cavity models taken out from the negative type. FIG. 5 shows a manufacturing process for molding the tooth model A. In the figure, 11 and 11 'are negative molds made of silicone, and 12 is a resin injection port.

In this example, first, a melted wax material is injected from the wax injection port 7 of the negative molds 6 and 6 ′ to mold and take out the wax pulp model 10.

Separately, the enamel part 1 of the tooth model A is formed with a synthetic resin, and the enamel part 1 is placed at a fixed position (cap part) in the negative molds 11 and 11 ′ of the tooth.
No. 0 guide 8 is placed in a fixed position (the medullary angle of the dental pulp cavity model 10 is designed so as not to reach the boundary line between the enamel part and the dentin part), and then the synthetic resin injection port 12
A synthetic resin that constitutes the dentin part 2 of the tooth model A is injected from.

Next, after curing the synthetic resin, the negative molds 11 and 11 'are opened,
The tooth model A taken out is heated to 90 ° C., and the internal wax (melting point 70 ° C.) is ejected from the apex under reduced pressure (5 mmHg) to obtain a tooth model A in which only the apex is open. It was

If a transparent material is used for the synthetic resin forming the dentin part 2, a product in which the pulp cavity 4 is transparent and can be seen from the outside can be obtained.

If a small amount of wax remains inside, inject a solvent such as petroleum benzine under reduced pressure, melt the wax, and eject it again under reduced pressure to completely remove the internal wax and completely The pulp cavity 4 is accurately completed. Further, as a method of removing wax, a method of blowing off with an air gun or a method of dissolving with a solvent can be applied.

Both the enamel part and the dentin part are formed of a synthetic resin material, but as with a known tooth model, the enamel part and the dentin part are naturally formed to have a hardness difference.

Epoxy, polyester, polyurethane, etc. are used as the synthetic resin, and inorganic fillers such as silica, alumina, zirconium, etc. or Aerosil (silica + alumina) and ethylene glycol dimethacrylate or other two or more It is advisable to add a vinyl monomer having a functional group or the like to finish the product to an appropriate hardness.

(Effects) According to the method of the present invention, like the natural tooth, a tooth model having a pulp cavity in which only the root apex is opened can be efficiently manufactured.

The product of the present invention is an undivided tooth model that accurately represents the pulp cavity of a natural tooth, obtained as an integrally molded product, and the enamel part and the dentin part are mixed with an organic composite filler or an inorganic filler in a synthetic resin. Since it can be molded with the above material so that the enamel part and the dentin part have different hardness, it can be widely used for endodontic treatment practice, in particular,
It can be used in the same way as natural teeth for root canal treatment training and training, which was difficult with conventional tooth models.

[Brief description of drawings]

1 is a front view of a tooth model according to the present invention, and FIG. 2 is a first view.
3 to 5 are sectional views showing a manufacturing process of the tooth model of FIG. 1, and FIGS. 6 and 7 are manufacturing process diagrams of a conventional tooth model. A: Tooth model 1 ... Enamel part 2 ... Dentin part 3 ... Boundary between enamel and dentin 4 ... Pulp cavity 5 ... Apical part 6, 6 '... Negative type 7 ... Wax injection port 8 ... Guide 9 ... Dividing surface part 10 ... Pulp cavity model 11, 11 '... Negative type 12 ... Synthetic resin injection port a ... Metal pulp b ... Dentin part c ... Open part d: boundary line between enamel and dentin e: root apex f: enamel part

Claims (1)

[Claims] 1. A dental pulp cavity model 10 made of wax is formed from the negative molds 6 and 6'having a dental pulp cavity shape. The dental pulp cavity model 10 is formed so that the medullary horn does not contact the enamel part 1 and the apical part. 5 is not covered by the dentin part 2 and is enclosed in the tooth negative molds 11 and 11 ′ together with the enamel part 1 which is synthetic resin molded in advance. A dentin part 2 is molded in a state where it is integrated with the enamel part 1 and the dental pulp cavity model 10 by injecting and curing a synthetic resin, and the integrated molded product is taken out, heated and heated. A method for manufacturing a tooth model, wherein the wax of 10 is melted and ejected from the apex portion 5 under reduced pressure to obtain a tooth model in which only the apex portion 5 is opened.