JP5173242B2 - Caries tooth for jaw model - Google Patents

Description

The present invention is a tooth used for a jaw and tooth model in which a student who aims to become a dentist experiences an intraoral work and practice treatment. More specifically, the present invention relates to a tooth composition used for experiencing the formation of an abutment, formation of a cavity, and the like.

Teeth for a jaw and tooth model for intraoral treatment practice are often made of epoxy resin and melamine resin, and are widely used.
However, since epoxy resin and melamine resin have different cutting feelings, even when practicing abutment tooth formation and cavity formation, it is often embarrassed by the different cutting feeling and workability when working in the actual oral cavity. It was. Specifically, epoxy resins and melamine resins tend to be soft and increase cutting, and natural teeth tend to be hard to cut as expected because they are hard. As a result, there is a possibility that it will be sharply cut and the shape cannot be made well.

As a result of a demand for a harder material, a composite type is commercially available. Even if it is a composite type tooth, the cutting feeling differs from natural teeth, so even if you practice practicing abutment and cavity formation, you will be embarrassed by the different cutting feeling and workability when working in the oral cavity. There were many things to do. The easy-to-understand expression has a feeling of slipping, and the cutting feeling is very different from natural teeth.
Also, it was not a reproduction of the caries cutting feeling, and it was not practiced to treat carious teeth.

In Japanese Utility Model Laid-Open No. 1-90068, Vickers hardness in which phlogopite crystal [NaMg3 (Si3AlO10) F2] and lithia / alumina / silica-based crystal (Li2O.Al2O3.2SiO2, Li2O.Al2O3.4SiO2) are simultaneously precipitated on the enamel layer. It is composed of glass and ceramics controlled to 350-450, and the root layer is added with white, red and yellow colorants in the polyol (main agent), and further mixed with an isocyanate prepolymer (curing agent) to form a silicone rubber base. The dentin recognition layer, which is injected into the mold under vacuum, hardened at room temperature and prepared in advance, is interposed between the enamel layer and the root layer, and is bonded together, has an opaque color. It is shown that it is formed with a sex resin.
However, when the enamel layer is composed of phlogopite crystals or lithia / alumina / silica crystals, the cutting feeling is too hard compared to natural teeth, so it is not durable and the dentin recognition layer is adhesive. Since it was made of resin, the cutting feeling of the adhesive was too soft, so it was not durable.
Moreover, it was not a reproduction of the caries condition, and it was impossible to experience caries teeth.

  Japanese Patent Application Laid-Open No. 5-224591 shows that a tooth model having cutting ability very similar to natural teeth and suitable for dental education cutting practice is provided. As main constituent components, inorganic powder and cross-linked resin are contained in a weight ratio of 20% to 80% to 70% to 30%.

As the inorganic powder constituting the tooth model of the present invention, for example, alumina, zirconia, titania, silica and the like are introduced, and the inorganic powder is not limited to the above compounds, and various inorganic powders can be used.
However, since the cutting feeling is different from that of natural teeth, even when practicing abutment tooth formation and cavity formation, when working in the actual oral cavity, it was often embarrassed by the different cutting feeling and workability. Moreover, only an inorganic powder body is disclosed. It was not a reproduction of the caries condition, and I was unable to experience caries teeth.
Japanese Patent Laid-Open No. 5-216395 introduces the provision of a tooth model having a cutting ability very similar to that of natural teeth and suitable for dental education cutting practice and a method for manufacturing the same. Contains hydroxyapatite powder with a porosity of 40-80% and (meth) acrylic ester resin as a main component of the tooth model in a weight ratio of 20% to 80% to 50% to 50% It is what you are doing.
Conventional tooth models are not in a satisfactory state in terms of machinability. Therefore, although it has been shown that development of a tooth model similar to natural teeth in cutting ability is desired, it does not show a sufficient cutting feeling. Moreover, it was not a reproduction of the caries condition, and it was impossible to experience caries teeth.

JP-A-5-224591 provides a dental model that can be optimally used for a periodontal disease treatment practice of a dentist. As a constitution, at least the surface of the crown portion has a Knoop hardness of 70 or more, and at least the surface of the root portion has a Knoop hardness of 10 to 40.
In the text, there is a description that “it may be made of a material of any hardness, for example, metal, ceramics, resin, and may be a cavity from the viewpoint of the preparation method of the tooth model and economical viewpoint”. It has not been solved from the viewpoint of cutting feeling.
In JP-A-5-241498, JP-A-5-241499, and JP-A-5-241500, there are descriptions of inorganic fillers and hydroxyapatite fillers. It has not yet been resolved. Furthermore, it was not a reproduction of the caries state, and it was not possible to experience caries dental treatment.

Japanese Patent Application Laid-Open No. 2004-94049 describes an invention for providing a dental training model tooth that enables accurate shape measurement using a laser beam.
In the specification, “as the material constituting the crown surface of the model tooth of the present invention, generally known materials can be used, for example, ceramics or other porcelain or acrylic, polystyrene, polycarbonate, etc. , Acrylonitrile styrene butadiene copolymer (ABS), polypropylene, polyethylene, polyester, and other thermoplastic resin materials, melamine, urea, unsaturated polyester, phenol, epoxy, and other thermosetting resin materials, and their main raw materials Glass fiber, carbon fiber, pulp, synthetic resin fiber and other organic and inorganic reinforcing fibers, talc, silica, mica, calcium carbonate, barium sulfate, alumina and other fillers, pigments, dyes and other colorants, or What added various additives, such as a weathering agent and an antistatic agent, can be used. Is described with, but there is no description of the preferred material, it was not intended to resolve the grinding feel. Furthermore, it was not a reproduction of the caries state, and it was not possible to experience caries dental treatment.

There is no disclosure as a specific composition, and only the relationship between the crown portion and the root portion with respect to the cutting feeling is shown. It was not a reproduction of the caries condition, and I was unable to experience caries teeth.
Although the jaw model has these problems, there are almost no reports on research.

JP 2004-94049 A JP-A-5-241498 JP-A-5-241499 JP 5-241500 A JP-A-5-224591 JP-A-5-216395 JP-A-5-224591 Japanese Utility Model 1-90068

The conventional jaw tooth model has a different cutting feeling from natural teeth, so even if you practice abutment and cavity formation, you will be embarrassed by the different cutting feeling and workability when working in the oral cavity. There were many. The sensation of sliding and the sensation of easy cutting are different, and the cutting feeling is very different from natural teeth.
In order to experience the cutting feeling of natural teeth, some ideas such as cutting extracted teeth were seen. The extracted tooth is a material from the living body and has a hygiene problem, and it was necessary to prevent infection sufficiently. Moreover, if hygiene management was not performed sufficiently, there was a problem of corruption, and sufficient care was required for storage.

There is a demand for a method for experiencing the cutting feeling of a tooth without using a natural tooth, and there is a need for a jaw-like model-like tooth that can provide a cutting feeling similar to that of a natural tooth.
In particular, it is difficult to experience cutting of caries, and it is necessary to fully practice caries removal methods that are important in dental treatment. Since the carious part is softer than the normal dentin part, it is necessary to practice rather than cutting a normal tooth model. There is a need for teeth that carry out these exercises.

The present invention relates to a tooth for a jaw and tooth model for therapeutic practice, in which the enamel portion of the tooth is made of an inorganic fired body, the dentin portion is made of a resin or an inorganic fired body, and between or between the enamel part and the dentin part. Jaw characterized in that there is a pseudo carious portion on the periphery, the pseudo carious portion is made of a resin or an inorganic fired body, and the pseudo carious portion includes one or more of a coloring material, a fluorescent material, and an X-ray contrast material. It is a tooth for a tooth model.
Furthermore, it is preferable that the enamel part, the dentin part, and the pseudo caries part are easily cut in this order.

The present invention is a tooth for a jaw and tooth model for treatment practice, wherein the composition of the tooth enamel portion is made of an Al ₂ O ₃ powder fired body.

The present invention is a tooth for a jaw tooth model for treatment practice,
Jaw teeth characterized in that the composition of the tooth dentin portion is made of any of acrylic, epoxy, and melamine, and the composition of the tooth enamel portion is made of an Al ₂ O ₃ powder fired body having a primary particle diameter of 0.1 to 1.0 μm This is a model tooth.

The present invention is a tooth for a jaw tooth model for treatment practice,
The composition of the tooth dentin portion is composed of an Al ₂ O ₃ powder fired body having a primary particle size of 1.0 to 8 μm, and the composition of the tooth enamel portion is composed of an Al ₂ O ₃ powder fired body having a primary particle size of 0.1 to 1.0 μm. This is a tooth for a jaw model.

The present invention is a tooth for a jaw tooth model for treatment practice,
The enamel part of the tooth is made from a sintered body of Al ₂ O ₃ powder, the dentin part is made from a resin mixed with inorganic or organic powder, and there is a pseudo caries part between the enamel part and the dentin part or at the edge thereof, A tooth for a jaw and tooth model, wherein a carious portion is made of a resin, and the pseudo carious portion includes one or more of a UV excitation type fluorescent material and an X-ray contrast material.

The present invention provides a tooth for a jaw and tooth model, wherein a pseudo carious portion has a dentin side around a transition portion between an enamel portion and a dentin portion on a tooth surface.
The enamel part is made from an Al ₂ O ₃ powder fired body,
Dentin part is made from resin, resin mixed with inorganic or organic powder, inorganic fired body,
A tooth for a jaw and tooth model in which a caries part is reproduced by applying or impregnating a caries part reproducing material containing at least one of a coloring material, a fluorescent material, and an X-ray contrast material on the dentin part. . The caries portion is a method for reproducing the caries portion, and is a caries portion reproduction material including any one or more of a coloring material, a fluorescent material, and an X-ray contrast material applied or impregnated into the dentin portion.

By forming an abutment tooth and a cavity using the tooth of the present invention, a cutting feeling similar to that of a natural tooth can be experienced quickly, and the formation experience can be easily performed. Moreover, these formation techniques can be acquired quickly.
The jaw model is the hardest substitute for natural teeth in the human body, and ordinary materials feel soft when cutting, but can provide the same cutting feeling as natural teeth. The cutting body can have the same experience in the same environment as the human oral cavity, which is cutting using diamond abrasives (using air turbine) that rotates at a high speed of 400000 rpm.

Since the tooth is brought into contact with a cutting body that rotates at a high speed during formation, compatibility with the jaw is important, and can be formed by casting or the like, but CIM that can be precisely formed is preferable.
Furthermore, the shape of the crown of the tooth model is also important, and it is important that the ridges, fossa, and cusps are accurately expressed as the objective of abutment tooth formation and cavity formation. ing.
The tooth of the present invention can be made white, ivory and milky white by using an inorganic pigment in the same manner as the tooth, and can have a more realistic cutting experience.

By changing the cutting feeling of dentin and enamel, a cutting feeling similar to that of natural teeth can be obtained, and by experiencing the uncomfortable feeling of cutting moving from enamel to dentin, it is possible to practice appropriate treatment.
The hardness of enamel can be easily reproduced, and the difference in hardness between dentin and enamel can be easily reproduced.

If there is no caries in cutting teeth, it is not usually cut. In that sense, the reproduction of carious teeth is an important issue, and the reproduction of carious teeth has been demanded. It was required to reproduce the cutting feeling of the carious portion with respect to the caries. Furthermore, in order to remove the caries portion accurately, a confirmation method has been required.
In dental treatment, it is important to completely remove caries, and teeth for practicing them have been sought.

  The present invention is a tooth for a jaw and tooth model for intraoral treatment practice, and a jaw part and a mannequin part can be appropriately selected. However, it is important to take measures to confirm the suitability for selection. For example, it is important to appropriately match the size of the tooth insertion opening.

The thing used as a tooth composition is a composite in which an inorganic powder fired body, a resin, or a resin and an inorganic or organic powder are mixed.
The tooth composition is preferably an inorganic powder fired body, preferably made of alumina, and the primary particle diameter is preferably 0.2 to 5 μm. It is not hindered to add a metal oxide typified by silica to the tooth composition to such an extent that the cutting feeling of the alumina fired body is not impaired. By changing the primary particle diameter of the alumina between the tooth dentin portion and the tooth enamel portion, it is possible to show a difference in cutting feeling. This can be realized by making the particles of the tooth enamel part coarser than the tooth dentin part.

It is that the composition of the tooth enamel portion is fired from the Al ₂ O ₃ powder of primary particle diameter 0.1 to 0.8 [mu] m, and that preferably the calcining Al ₂ O ₃ powder of primary particle diameter 0.1 to 0.5 [mu] m, more preferably Is firing from an Al ₂ O ₃ powder having a primary particle size of 0.2 to 0.3 μm.
Both enameldentins are fired at a firing temperature of 1300-1600 ° C.
The preferred firing temperature for the enamel portion is 1400-1600 ° C, and the preferred firing temperature for the dentin portion is 1300-1500 ° C. The firing temperature is closely related to the cutting feeling and must be adjusted according to the particle size and raw material lot. Similarly, the mooring time at the firing temperature is closely related to the cutting feeling and must be adjusted according to the particle size and raw material lot.
The Vickers hardness of the tooth dentin portion and the tooth enamel portion is 300 to 1000.

It is sufficient that the sintered body of the alumina powder is used for the crown portion of the tooth model portion, but it is preferable that most of the tooth is made of the composition of the present invention.
It is preferred to make the present invention with CIM technology.
CIM is a molding technique manufactured in the following process.
(1) Alumina is kneaded with a resin such as a thermoplastic resin or wax (which decomposes by heat up to about 600 ° C.) to produce pellets.
(2) A mold for injection molding having a fixed shape is produced, and the pellet produced in (1) is injection molded.
(3) After molding, the resin is degreased (the temperature is raised to decompose the resin component).
(4) Next, the remaining inorganic powder body is fired and baked and molded until a shape can be imparted.
Using this technique to produce a tooth is the most suitable method in view of moldability and the like.

As the resin composition used for the tooth portion of the present invention, conventionally used resins, organic powders, or mixtures of inorganic powders and resins can also be used.

As the resin used for the tooth portion of the present invention, a thermosetting resin or a thermoplastic resin can be used. A thermosetting resin or a resin containing a crosslinking agent is preferred. Furthermore, a melamine resin and an epoxy resin are preferable.
Thermoplastic resin refers to a resin that can be molded to a degree of thermoplasticity by applying heat, and thermosetting resin refers to a resin that crosslinks and cures when heated. Specifically, acrylic, styrene, olefin, vinyl chloride, urethane, polyamide, polybutadiene, polyacetal, saturated polyester, polycarbonate, polyphenylene ether and the like can be used as appropriate.
In particular, acrylic, styrene, urethane, and polyamide resins are preferable.
Mixing these thermoplastic resins with a crosslinking agent is preferable because it has the same properties as the thermosetting resin. That is, tooth cutting can be practiced without melting by the heat generated during cutting.

A thermosetting resin is preferred to a thermoplastic resin. This is because the thermosetting resin does not dissolve in a solvent after molding and does not soften even when reheated. A urea resin, a melamine resin, a phenol resin, an epoxy resin, and the like can be typically used, and a melamine resin and an epoxy resin are preferable. Most preferred is an epoxy resin.

In addition, inorganic or organic powders can be mixed with these resins in order to improve the cutting feeling. An inorganic powder is a thing with a particle size of 0.1-100 micrometers centering on ceramics and glass, and a composition is not specifically limited. A preferred particle size is 0.1 to 10 μm.
Specific inorganic powders are quartz, amorphous silica, clay, aluminum oxide, talc, mica, kaolin, glass, barium sulfate, zirconium oxide, titanium oxide, silicon nitride, aluminum nitride, titanium nitride, silicon carbide, boron carbide, carbonized Inorganic substances such as calcium, hydroxyapatite and calcium phosphate.
As specific organic powders, organic substances such as polymers or oligomers such as polymethyl methacrylate, polyethyl methacrylate, polyvinyl chloride, polystyrene, polyester and nylon; and organic-inorganic composites can be suitably used.
These powders may be used alone or in combination of two or more without any problem. Moreover, it is more preferable to use those powders that have been surface-treated with a titanate coupling agent, an aluminate coupling agent, or a silane coupling agent that are used as publicly known. The mixing ratio can be appropriately selected as necessary, and may be selected from a range of 1 to 90%, for example. Preferably it is 60 to 95%.

The inorganic fired body, the resin, and the composite composition used for the pseudo carious portion can use the same composition as the enamel portion and the dentin portion.
Compared to the enamel portion and the dentin portion, it is preferable that the pseudo carious portion is easy to cut.
It is preferable that the enamel portion, the dentin portion, and the pseudo carious portion are easily cut sequentially.
Specifically, the enamel part and the dentin part are an inorganic fired body and the pseudo caries part is a resin or composite, the enamel part is an inorganic fired body, the dentin part is a composite, and the pseudo caries part is easier to cut than the resin or dentin part. A composite in which the enamel portion is composite and the dentin portion is easier to cut than the enamel portion, and the pseudo carious portion is easier to cut than resin or dentin.
Even when the same composition is used for the same tooth, there is no problem as long as it can be discriminated using a colorant or a fluorescent material. It becomes practice to judge the caries part by color tone.
For example, a coloring agent, a fluorescent material, an X-ray contrast material, or the like can be dispersed in a solvent and impregnated with dentin to form a pseudo carious portion. This method is preferable because a pseudo carious portion can be easily produced.

It is preferable to impart X-ray contrast properties to the pseudo-carious portion. X-ray contrast properties are achieved by including X-ray contrast materials such as SrO, BaO, ZnO, ZrO2, La2O3 and other heavy metal element oxides. Can do.
By giving X-ray contrast property to the pseudo caries portion, the caries removal state can be confirmed by X-ray imaging after the treatment practice. It is good for evaluation after cutting.
It is preferable to apply an X-ray contrast medium to the pseudo-carious portion. The X-ray contrast medium is achieved by including an X-ray contrast medium such as SrO, BaO, ZnO, ZrO2, La2O3 and other heavy metal element oxides. Can do. SrO, BaO, ZnO, ZrO2, La2O3 are preferable, and ZnO and ZrO2 are more preferable.
The average particle size of the colorant, the fluorescent material, and the X-ray contrast material is 0.1 to 30 μm, preferably 1.0 to 10 μm, and more preferably 1.0 to 5.0 μm. The colorant, the fluorescent material, and the X-ray contrast material may be dyes.

It is preferable to add a fluorescent material to the pseudo-carious portion. More preferably, the fluorescent material is a UV-excited fluorescent material, and more preferably a UV-excited fluorescent pigment. In normal cutting, it does not emit fluorescence and can be confirmed by emitting fluorescence with black light.
Fluorescent materials sold by major manufacturers such as ARBROWN CO., LTD. Can be used. Further, any fluorescent pigments sold by Shinroihi Co., Ltd. can be used without particular limitation as long as they are dispersed in a base resin or the like and emit fluorescence.
As the type of UV-excited fluorescent material, UV-excited organic fluorescent pigments or inorganic fluorescent pigments can be used.

It is preferable to add a coloring material to the pseudo carious portion. It may be a dye or a pigment. The caries site can be visually confirmed by coloring and can be easily cut. Preferably, a dark colorant is preferable, and a black colorant is particularly preferable.
The coloring material is preferably combined with a fluorescent agent or an X-ray contrast material.
Furthermore, it is also preferable to use a fluorescent agent or an X-ray contrast medium as a color that is substantially the same as a dentin color or an enamel color, for the practice of distinguishing the pseudo caries portion from a different feeling due to the cutting feeling.
When the pseudo carious part is made of a material different from the dentin part or enamel part, combining the pseudo carious part with a fluorescent agent or an X-ray contrast material, the teeth are cut around the different sensations of the material, and the caries is carved. Practice to remove the part is possible. Later, using black light or X-ray photography, it can be confirmed whether the caries has been completely removed.

The pseudo caries portion is preferably provided around the boundary between the enamel portion and the dentin portion. In this case, the pseudo caries portion is preferably provided in the vicinity of the sharpened tip of dentin, and is preferably provided on the dentin side rather than on the enamel side.
Moreover, a pseudo carious part can also have in the dentin side around the transition part of the enamel part of a tooth surface, and a dentin part. In this case, root caries at the root is reproduced.

Next, the method for producing a tooth for a jaw and tooth model of the present invention will be described below.
(When the enamel part is an inorganic powder fired body and the dentin part is a composite)
A composite (5% carbon black, 10% zinc oxide, 30% UV-excited inorganic fluorescent pigment, 30% on a part of the dentin side of the Al ₂ O ₃ (average particle diameter 5 μm) powder fired body molded into an enamel partial shape, Apply and harden caries reproduction material of 55% epoxy, small amount of catalyst) and place in dental mold, dentin part of composite (5% titanium oxide, 70% silica powder (5μm), 25% epoxy, small amount of catalyst) To prepare a tooth for a jaw and tooth model.

(When enamel part and dentin part are both composite)
Composite (5% titanium oxide, 70% silica powder (5 μm), 25% epoxy, small amount of catalyst) is molded into an enamel shape, and composite (carbon black 5%, zinc oxide 10%, UV excitation) is partially formed on the dentin side. Apply and cure caries reproducible material of inorganic fluorescent pigment of 30% type, epoxy 55%, small amount of catalyst) and place in dental mold, composite (5% titanium oxide, 70% silica powder (5μm), epoxy 25%, a small amount of catalyst) was pushed in to prepare a tooth for a jaw and tooth model.
The molding of the enamel part and the molding of the dentin part are preferably performed by injection molding.

(When enamel part and dentin part are both inorganic powder fired bodies)
An Al ₂ O ₃ (average particle diameter 5 μm) powder fired body molded into a dentin partial shape and an enamel partial shape is produced, and a composite (carbon black 5%, zinc oxide) is formed in a part of the dentin portion enamel crown. 10%, UV excitation type inorganic fluorescent pigment 30%, epoxy 55%, small amount of catalyst) caries part reproduction material is applied and cured, and dentin part and enamel part are bonded with epoxy resin to form jaw tooth model tooth Was made.
After the enamel part and dentin part are integrally molded or integrated, when a pseudo caries part is provided, a tooth is created by providing a cavity in the pseudo caries part and a hole is made up to the caries part, and injecting a caries part reproduction material. can do. A small hole may be made in a thin part from the enamel part to the dentin part, and the caries part reproduction material may be injected. This thin part is called a fossa in a natural tooth, and tends to be a caries manifestation part, and is preferably a tooth with more reproducibility. Even if this hole exists in an interdental part, it is preferable. This is because, for example, anterior teeth tend to cause dental caries between adjacent teeth, and it is preferable to have a reproducible tooth.

Many combinations other than these methods can be implemented. A simple combination is shown below.
Table 1 shows a combination table of the enamel part, dentin part, and pseudo caries part.

This combination table will be described. Each number shown in the upper table is the number shown in the lower table. As shown in the table below, the enamel portion is displayed as “1”, the dentin portion is displayed as “2”, and the pseudo carious portion is displayed as “3”.
In Example 1, the enamel part, the dentin part, and the pseudo caries part are all made of an inorganic powder fired body. Further, as shown above, it is preferable that the enamel portion, the dentin portion, and the pseudo carious portion become softer in order (easier to cut). For example, when it is made of alumina powder, the calcined product is cut by roughening the composition of the enamel part to 0.5 μm primary particles, the composition of the tooth dentin part to 2 μm primary particle diameter, and the composition of the pseudo caries part to 5.0 μm primary particle diameter. It can be configured easily and caries can be detected during the cutting process.

In Example 2, the enamel part and the dentin part are made of an inorganic powder fired body. The pseudo caries portion is made of composite. Further, as shown above, it is preferable that the enamel portion and the dentin portion become softer in this order.
In Example 3, the pseudo carious portion of Example 2 is made of a thermosetting resin or a thermoplastic resin with a crosslinking agent. Both Example 2 and Example 3 are preferable combinations.
Other examples are similarly fired inorganic powder, composite, "thermosetting resin, thermoplastic resin with cross-linking agent", thermoplastic resin, dentin part impregnation (*), enamel part, dentin part, pseudo caries part The preferred material was chosen.

“Dentin part impregnation (*)” corresponds to only the pseudo-carious part, and is prepared by impregnating the prepared dentin part with a coloring material, a fluorescent material, and an X-ray contrast material. Although this method cannot make a difference from the dentin portion due to the ease of cutting, etc., when the tooth composition is an inorganic powder fired body, it is possible to practice cutting close to natural teeth compared to a conventional tooth model.
It is preferable that the pseudo carious portion is softer (easier to cut) than the enamel portion or the dentin portion. It is preferable that the enamel part, the dentin part, and the pseudo carious part become softer in order (easy to cut). This is because it becomes practice to judge caries cutting with the sense of abrasive.
The enamel portion is preferably an inorganic powder fired body, composite, “thermosetting resin, thermoplastic resin with a crosslinking agent”, more preferably an inorganic powder fired body or composite, and further preferably an inorganic powder fired body. It is preferable that the enamel is hard and the cutting sensation approximates.
The dentin portion is preferably an inorganic powder fired body, composite, "thermosetting resin, thermoplastic resin with a crosslinking agent", or a thermoplastic resin, and further an inorganic powder fired body, composite, "thermosetting resin, thermoplastic resin with a crosslinking agent. "Is preferred, more preferably an inorganic powder fired body and composite, and still more preferably an inorganic powder fired body. This is because the dentin is similar in feeling. The thermoplastic resin is enough to endure use. It is often softened during cutting.
The pseudo caries part can be "thermosetting resin, thermoplastic resin with cross-linking agent", thermoplastic resin, "impregnating dentin part", etc., "thermosetting resin, thermoplastic resin with cross-linking agent", thermoplastic resin Are preferred. Simply impregnating does not change the cutting sensation, so it cannot be used to practice different cutting sensations.

Example 1
700 g of Al ₂ O ₃ powder having a primary particle size of 0.3 μm and 300 g (30%) of stearic acid were heated and kneaded and injected into an enamel mold. The injected molded body was degreased at 600 ° C. for 3 hours and fired at 1500 ° C. The mooring time at the firing temperature was 15 minutes. As a result of natural cooling, the enamel part was completed. A small amount of an epoxy resin mixed with 10% of UV-excited inorganic fluorescent pigment and 0.2% of carbon black was attached to the portion where the enamel-shaped dentin comes into contact, thereby forming a pseudo caries portion.
Next, the enamel part was placed in a tooth-shaped mold, and the remaining dentin part was injected with an ivory colored epoxy resin to complete. A dental diamond bar was used for the test.

(Examples 2 to 6)
Following Example 1, Examples 2 to 6 were performed. Table 2 shows the differences from the examples.

The evaluation of machinability, abutment tooth formability, and cavity formability was performed based on closeness to natural teeth, and all of them were good results. In particular, the dentin enamel transferability was good by confirming whether the cutting feeling approximated that of a natural tooth when the abrasive transferred at the interface between the dentin layer and the enamel layer.
It was confirmed that the black part was deleted in the caries part and the caries part was correctly removed with the black light.

(Examples 7 to 12)
The enamel part is the alumina powder fired body of Examples 1 to 6, and a composite in which 75% alumina powder and 25% epoxy resin are mixed in the dentin part, and the enamel-shaped part dentin is in contact with the pseudo carious part is UV excitation type. A small amount of an epoxy resin mixed with 10% of the inorganic fluorescent pigment was used as a pseudo caries portion. Both pseudo caries and dentin were colored ivory.
The molding method was carried out according to Example 1. As the mold, a tooth mold was used.
The evaluation of machinability, abutment tooth formability, and cavity formability was performed based on closeness to natural teeth, and all of them were good results. In particular, the dentin enamel transferability was good by confirming whether the cutting feeling approximated that of a natural tooth when the abrasive transferred at the interface between the dentin layer and the enamel layer.
The cutting feeling of the caries part was different, and it was confirmed that the caries part was accurately removed with black light. Experts could easily find the sensation of the caries, but beginners could cut the caries as they practiced.
This confirms that it is easy to experience cutting of caries.

(Example 13)
The enamel part and the dentin part were carried out with the same composition as in Example 7 to prepare a tooth using a composite in which pseudo-carious part was mixed with 20% zinc oxide and 80% epoxy resin. The molding method was carried out according to Example 1. As the mold, a tooth mold was used. As a test, caries were removed and the dental model was photographed with a dental X-ray. As a result, the caries removal situation could be easily photographed.

Claims (2)

A tooth for a jaw and tooth model for treatment practice,
And the enamel portion of the tooth, is composed of a dentin portion, and during or pseudo caries portion provided on the periphery of the enamel portion and the dentin portion,
The composition of the enamel part is composed of an Al ₂ O ₃ powder fired body,
The pseudo caries portion is made of resin ,
The enamel part, the dentin part and the pseudo carious part are configured to be soft in this order,
The pseudo caries portion is configured to have the same color as the enamel portion or the dentin portion,
A tooth for a jaw and tooth model, wherein the pseudo carious portion includes at least one of a UV-excited fluorescent material and an X-ray contrast material . The tooth for a jaw and tooth model according to claim 1, wherein the dentin portion is made of a composite of a resin and an inorganic powder or an organic powder.