JP4249054B2 - Multilayer model teeth for dental training - Google Patents

Description

  The present invention relates to a multilayer model tooth for dental training.

Conventionally, dental training model teeth have been widely used in educational fields such as dental universities and dental technician schools. For example, there are those described in the following patent documents.
JP-A-5-241499 JP-A-5-241500

The dental training multilayer model tooth described in Patent Document 1 is a model tooth having a cutting feeling close to that of a natural tooth obtained by changing the material of the crown surface layer and the root part. Moreover, the multilayer model tooth for dental training described in the said patent document 2 is a model tooth of the layer structure nearer to the natural tooth which changed the material of the crown part surface layer and the root part surface layer.
These model teeth have a multilayer structure similar to natural teeth, and the thickness of the natural teeth is reproduced even in the crown enamel layer. Therefore, the thickness of the enamel layer near the tooth neck line is very thin, about 0.1 mm to 0.5 mm, and this enamel layer is further reduced in thickness as it approaches the tooth neck line. It disappears at. By reproducing such a multilayer structure of natural teeth, the crown enamel layer near the cervical line is thin and has a sharp wedge shape with the cervical line at the tip. There was a problem that the enamel layer near the cervical line was easily lost due to the cutting practice for removing the enamel layer near the cervical line in restoration training or the like.

  An object of the present invention is to provide a dental multi-layer model tooth having a crown portion that reproduces a multilayer structure similar to a natural tooth and that is easily lost even by cutting practice such as dental restoration practice.

  That is, the multilayer model tooth for dental practice of the present invention is a dental practice multilayer comprising a crown part and a root part artificially imitating an enamel layer as a surface layer and a dentin layer as an internal layer. In the model tooth, the enamel layer extends from the tip of the model tooth beyond the neckline to the root portion side, and at least the portion adjacent to the crown portion and the surface of the root portion in the vicinity thereof, It is formed integrally so as to be covered with the enamel layer of the crown.

  The present invention is also characterized in that in the multilayer model tooth for dental practice having the above-mentioned features, the thickness of the enamel layer covering the root surface of the cervical line is 0.02 mm to 0.3 mm. It is also what you do.

  In the case of the multilayer model tooth for dental practice of the present invention, the enamel layer extends from the tip of the model tooth to the root part beyond the neck line, and at least the surface of the root part adjacent to the crown part and the vicinity thereof. Because it is a structure that is integrally formed so as to be covered with the enamel layer, chipping of the enamel layer is effectively prevented during cutting practice of the crown enamel layer near the tooth neck. Can do good practice.

The multilayer model tooth for dental practice of the present invention was integrated with a crown part formed by artificially imitating an enamel layer as a surface layer and a dentin layer as an internal layer, and the crown part. It consists of a tooth root.
The crown portion has a multi-layered structure having an enamel layer on the surface and a dentin layer inside like a human natural tooth. The thickness of the enamel layer is the thickest at the tip of the model tooth, and gradually decreases as it approaches the root, and the thickness of the enamel layer near the cervical line that forms the boundary between the root and the crown is 0.02 to 0 It is very thin, about 3mm.
The enamel layer that is thinnest in the vicinity of the tooth neck line forms a portion adjacent to the crown portion in the root portion and a root surface portion in the vicinity thereof. At this time, the enamel layer that is thinnest near the tooth neck line is extended to the root side while maintaining its thickness, or while gradually increasing in thickness, or gradually decreasing the thickness, It may extend to. If the thickness of the surface layer of the root is too thin, the effect of preventing chipping of the crown enamel layer is lost, and if it is too thick, a multilayer structure different from that of natural teeth is formed. Therefore, although the thickness and width are appropriately selected depending on the desired model tooth shape, the thickness of the surface layer is about 0.02 mm to 0.3 mm, preferably about 0.05 mm to 0.2 mm. Here, the portion adjacent to the crown portion of the root portion and the vicinity thereof refer to a range from the tooth neck line of the tooth root portion to about 5 mm in the root end direction, and if this width is too narrow, The crown enamel layer tends to be missing. Therefore, the width of the surface layer of the tooth root is preferably 0.5 mm or more, and more preferably 1 mm or more. It is desirable that the surface layer of the tooth root portion is formed over substantially the entire circumference of the tooth root portion, but the surface layer of the tooth root portion may be partially formed.

The enamel layer and dentin layer that form the crown part may be formed of different materials, or may be the same material, but the enamel layer provides a cutting feeling closer to natural teeth. It is desirable to use a harder material than the dentin material.
The hardness of the enamel layer depends on the material used. For example, when the resin material is used as a standard, the hardness is about 110 to 130 on the Rockwell M scale (according to JIS-K6911), and the hardness of the dentin layer. Is preferably about 70 to 110. Furthermore, by making the hardness difference between the enamel layer and the dentin layer 10 to 60, preferably 20 to 50, it is possible to obtain a cutting feeling closer to natural teeth.

Hereinafter, the present invention will be described with reference to the drawings. Fig.1 (a) is a figure which shows an example of the external appearance shape of the dental practice-like model tooth | gear of this invention, (b) is sectional drawing which shows the internal structure. Moreover, Fig.2 (a) is a figure which shows an example of the external appearance shape of the conventional dental practice-like model tooth, (b) is sectional drawing which shows the internal structure.
As shown in FIGS. 1 (a) and 1 (b), the multilayer model tooth for dental training of the present invention is formed by artificially combining an enamel layer (3) as a surface layer and a dentin layer (4) as an inner layer. The enamel layer (3) extends from the tip of the model tooth to the root (2) side beyond the neck line (6). At least the surface adjacent to the crown portion (1) and the surface of the root portion (2) in the vicinity thereof are covered with the enamel layer (3) of the crown portion (2). And in this invention, the thickness of the enamel layer (surface layer (5) of a tooth root part) which covers the tooth root part surface in the position of a tooth neck line (6) is 0.02 mm-0.3 mm.

The crown portion (1) is provided with fine irregularities on its surface with an average roughness of the center line of Ra 0.1 micrometer or more and less than 10 micrometers, preferably 0.15 micrometers or more and 5 micrometers or less. It may be able to reflect.
Moreover, the surface part may be provided with a dent or a discolored part due to deposition, or a deposit imitating tartar.
Furthermore, it is possible to provide a discolored portion simulating caries at the interface between the enamel layer (3) and the dentin layer (4), and a pulp cavity may be formed inside the dentin. The crown portion (1) is connected to the root portion (2) and can be installed on a predetermined jaw model.

  The root portion (2) connected and integrated with the crown portion (1) is not particularly limited in structure other than the portion adjacent to the crown portion and the surface layer in the vicinity thereof, and may be a single layer structure. A multilayer structure may be used, a structure having a plurality of roots closer to natural teeth, or a single root structure obtained by simplifying natural teeth. Further, a pulp cavity or a root canal that simulates a natural tooth may be formed inside. Furthermore, it is also possible to provide a layer imitating a cementitious layer on the surface layer other than the surface layer adjacent to the crown portion and the vicinity thereof.

  As a raw material of such a model tooth, generally known materials can be used. In the case of an enamel layer of a crown portion, for example, porcelain such as ceramics or acrylic, polystyrene, polycarbonate, polyester, etc. Thermoplastic, synthetic resin materials such as melamine, urea, unsaturated polyester, phenol, epoxy, etc., polymerizable monomer materials such as trimethylolpropane trimethacrylate and dimethacryloxyethyltrimethylhexamethylenediurethane, and more Main raw materials for glass fiber, carbon fiber, pulp, synthetic resin fiber and other organic and inorganic reinforcing fibers, talc, silica, mica, calcium carbonate, barium sulfate, alumina, glass powder and other fillers, pigments and dyes Various additives such as colorants such as weathering agents and antistatic agents Agent can be used with the addition of.

The above-mentioned various materials can also be used as the material for forming the dentin layer and the root of the crown.
Here, in order to obtain a model tooth having a cutting feeling closer to that of a natural tooth, a hard material in which an inorganic material such as silica is filled in the polymerizable monomer material described above is used for the enamel layer of the crown portion, and the dentin layer It is desirable to use a material having a relatively low hardness, mainly made of acrylic, melamine, epoxy, or the like, as a material for the tooth root.
The color tone of these materials is not particularly limited, but is appropriately adjusted to a desired color tone. The method of toning is not particularly limited, and may be adjusted to a desired color tone by appropriately combining various known pigments and dyes.

Such a model tooth manufacturing method is appropriately selected depending on the material to be used. For example, when synthetic resin is used as a main raw material, a known method such as general injection molding or press molding can be applied.
Here, a manufacturing method by a general injection molding method will be described.
First, an injection mold for forming a shape in which the dentin layer and the root portion are integrated is filled and solidified with the raw material to be the dentin layer and the root portion, and the dentin layer and the root portion are integrated. Create a molded product. Next, after this molded product is mounted at a predetermined position in an injection mold for molding the enamel layer shape, the material to be the enamel layer is filled in the mold, and consists of a dentin layer and a root portion. The enamel layer of the outer layer of the molded product is laminated and integrated. At this time, the surface layer of the tooth root portion of the molded product to be mounted on the mold for forming the enamel layer is formed so that the surface layer described above is formed, so that the surface layer of the tooth root portion is simultaneously filled with the material of the enamel layer. It is formed.

By such a method, the multilayer model tooth for dental practice of the present invention can be easily manufactured. However, the present invention is not limited to this method, and after forming the enamel layer first, It is also possible to integrate the dentin layer of the tooth part and the root part, and after forming the dentin layer and the enamel layer of the crown part by the injection molding method etc., the root part formed separately Can be joined and integrated, or the enamel layer, dentin layer, and root portion can be shaved from the blocks of the respective materials, and these can be joined and integrated.
Here, the explanation was made based on the drawing of the front teeth, but the multilayer model tooth for dental training of the present invention is not limited to the front teeth, and the same effect can be obtained also in the molars.

[Example 1]
Filled and solidified into a mold that has a shape after the enamel layer, dentin layer, and tooth root part are integrated, and the dentin layer and tooth root part are integrated. A molded product was obtained. The molded product obtained by cutting and removing the portion that becomes the enamel layer and the surface layer of the tooth root portion of the obtained molded product is mounted again in the previous mold, and dimethacryloxyethyl trimethylhexa that becomes the enamel layer. By filling and solidifying a material in which methylene diurethane was mixed with silica, a multilayer model tooth for dental practice in which the dentin layer, root part and enamel layer were integrated was obtained. At this time, the surface layer thickness of the tooth root portion was set to 0.1 mm and the width (distance from the tooth neck line to the root end direction) was set to about 2 mm.
As a result of cutting practice of the enamel layer in the crown near the tooth neck using this dental model multilayer model tooth, it was possible to carry out good practice without any chipping of the enamel layer.

[Example 2]
As a result of cutting practice of the crown enamel layer in the vicinity of the cervical region using a dental dental multilayer model tooth prepared in the same manner as in Example 1 except that the surface layer thickness of the tooth root part was 0.05 mm, enamel It was possible to conduct good practice without any lack of quality layer.

[Comparative Example 1]
A dental crown in the vicinity of the cervical region using a conventional dental training multilayer model tooth having the structure shown in FIGS. 2 (a) and 2 (b), which was prepared in the same manner as in Example 1 except that the surface layer was not formed on the root portion. As a result of cutting practice of the part enamel layer, lack of the enamel layer was partially observed, and good practice could not be performed.

(A) is a figure which shows an example of the external appearance shape of the dental practice-like model tooth | gear of this invention, (b) is sectional drawing which shows the internal structure. (A) is a figure which shows an example of the external appearance shape of the conventional dental practice-like model tooth, (b) is sectional drawing which shows the internal structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crown part 2 Tooth root part 3 Enamel layer 4 Dentin layer 5 Surface layer 6 of a root part Tooth neck line

Claims (2)

In a dental multi-layer model tooth composed of a crown part and a root part artificially imitating an enamel layer as a surface layer and a dentin layer as an internal layer, the enamel layer is a tip of the model tooth Extending to the root side beyond the cervical line, and at least the adjacent part of the crown part and the surface of the root part in the vicinity thereof are covered with the enamel layer of the crown part. A multilayer model tooth for dental practice, characterized by being integrally formed. The multilayer model tooth for dental training according to claim 1, wherein the thickness of the enamel layer covering the root surface of the cervical line is 0.02 mm to 0.3 mm.

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