Compression method tooth

Abstract

The compression molded tooth used for practicing dental cutting treatment of the present invention comprises a composition containing a powder or powders of saccharide, polysaccharide, protein, and/or glycoprotein each having a particle size of 1 to 100 m.

Claims

1. A compression molded tooth used for practicing dental cutting treatment consisting of a compression molded article of a composition consisting of a powder or powders of saccharide, polysaccharide, protein, and/or glycoprotein each having a particle size of 1 to 100 m.

2. The compression molded tooth according to claim 1, wherein the tooth has portions where the numbers of compression molding cycles are different.

3. The compression molded tooth according to claim 1, wherein the tooth comprises a first portion constituting an enamel tooth portion and a second portion constituting a dentin tooth portion, wherein the number of compression molding cycles for the first portion is larger than the number of compression molding cycles for the second portion.

4. The compression molded tooth according to claim 1, wherein the tooth has a third portion different from the first portion and the second portion therein.

5. The compression molded tooth according to claim 4, wherein the third portion constitutes a dental caries portion, a dental pulp portion, and/or a cutting target portion.

6. A method for producing a compression molded tooth according to claim 1 comprising: molding a crown side using a concave mold; and molding a root side using a convex mold.

7. The method for producing a compression molded tooth according to claim 6, wherein an enamel tooth portion closer to an occlusal surface is molded using a first convex mold, and then a dentin tooth portion is molded using a second convex mold.

8. The method for producing a compression molded tooth according to claim 7, wherein molding pressure for the first convex mold is 20 to 100 MPa; molding pressure for the second convex mold is 5 to 85 MPa; and the molding pressure for the second convex mold is lower by 15 MPa or more as compared with the molding pressure for the first convex mold.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a view of tooth morphology obtained by powder compression molding in a single layer;

(2) FIG. 2 is a production conceptual diagram of a tooth and a mold under powder compression molding in a single layer;

(3) FIG. 3 is a production conceptual diagram of a tooth and a mold under powder compression molding in a single layer;

(4) FIG. 4 is a view of tooth morphology obtained by powder compression molding in two layers of an enamel tooth and a dentin tooth;

(5) FIG. 5 is a production conceptual diagram of a tooth and a mold under powder compression molding in two layers of an enamel tooth and a dentin tooth;

(6) FIG. 6 is a view of tooth morphology obtained by powder compression molding in three layers of an enamel tooth, a dentin tooth, and a dental pulp (third layer);

(7) FIG. 7 is a production conceptual diagram of a tooth and a mold under powder compression molding in three layers of an enamel tooth, a dentin tooth, and a dental pulp (third layer); and

(8) FIG. 8 is a view of tooth morphology obtained by powder compression molding in three layers of an enamel tooth, a dentin tooth, and a dental caries (third layer).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(9) A compression molded tooth used for practicing dental cutting treatment of the present invention comprises a composition containing a powder or powders of saccharide, polysaccharide, protein, and/or glycoprotein each having a particle size of 1 to 100 m.

(10) Examples of the saccharide, polysaccharide, protein, and glycoprotein are as shown below.

(11) Examples of monosaccharides include trioses ketotriose (dihydroxyacetone) and aldotriose (glyceraldehyde), tetroses ketotetrose (erythrulose) and aldotetrose (erythrose and threose), pentoses ketopentose (ribulose and xylulose), aldopentose (ribose, arabinose, xylose, and lyxose), and deoxy sugars (deoxyribose), hexoses ketohexoses (psicose, fructose, sorbose, and tagatose), aldohexoses (allose, altrose, glucose, mannose, gulose, idose, galactose, and talose), and deoxy sugars (fucose, fuculose, and rhamnose), and heptoses sedoheptulose.

(12) Examples of polysaccharides include disaccharides sucrose, lactose, maltose, trehalose, turanose, and cellobiose, trisaccharides raffinose, melezitose, and maltotriose, tetrasaccharides acarbose and stachyose, other oligosaccharides fructo-oligosaccharide (FOS), galacto-oligosaccharide (GOS), and mannan-oligosaccharide (MOS), polysaccharides glucose: glycogen, starch (amylose and amylopectin), cellulose, dextrin, glucan (-1,3-glucan), fructose: fructan (inulin and levan -2.fwdarw.6), and N-acetyl glucosamine: chitinous substance, oligosaccharides fructo-oligosaccharide, galacto-oligosaccharide, and lactosucrose, deoxy sugars deoxyribose, fucose, rhamnose, uronic acid glucuronic acid and galacturonic acid, amino sugar glucosamine and galactosamine, sugar alcohol glycerin, xylitol, and sorbitol, lactone ascorbic acid (vitamin C), glucuronolactone, and gluconolactone, and polysaccharides starch, amylose, amylopectin, glycogen, cellulose, pectin, and glucomannan.

(13) A polymer compound in which a large number of L-amino acids, which are present in 20 types, are linked together (polymerized) in a chain may be used as a protein, and specifically, it is preferred to use powdered milk. The milk powder can be obtained directly from milk as a white product. Therefore, when the milk powder is used as a tooth material, it is not necessary to pass through steps such as extraction and coloration. Further, since it has not passed through steps such as extraction and coloration, it is possible to directly utilize the tooth material as a livestock food after use. Further, this is because, when preparing a compression molded tooth, steps other than compression molding are not required, and the hardness of the compression molded tooth can be changed only by adjusting compression pressure.

(14) A compound in which a sugar chain is combined with a part of an amino acid constituting a protein can be used as a glycoprotein, and specific examples include glucose, galactose, mannose, fucose, N-acetyl glucosamine, N-acetyl galactosamine, N-acetyl neuraminic acid, and xylose.

(15) Preferred saccharides, polysaccharides, proteins, and/or glycoproteins are sugar alcohol, a polysaccharide, and a protein. Specific examples of sugar alcohol include erythritol, glycerin, HSH, isomalt, lactitol, maltitol, mannitol, sorbitol, xylitol, and sucrose. Specific examples of polysaccharides include starch (amylose and amylopectin), glycogen, cellulose, chitin, agarose, carrageenan, heparin, hyaluronic acid, pectin, and xyloglucan. Specific examples of proteins include powdered milk. Among these, more preferred examples of sugar alcohol include maltitol, sorbitol, and xylitol; more preferred examples of polysaccharides include starch (amylose and amylopectin), glycogen, and cellulose; and more preferred examples of proteins include powdered milk.

(16) The compression molded tooth preferably contains a saccharide, a polysaccharide, a protein, and/or a glycoprotein in an amount of 10% by mass or more, more preferably 70% by mass or more, further preferably 98% by mass or more, and most preferably about 100% by mass except for a colorant and the like.

(17) The saccharide powder, polysaccharide powder, protein powder, and/or glycoprotein powder is a powder having an average particle size of 1 to 100 m, preferably 10 to 70 m. In this application, the average particle size may be measured according to ISO 13322-1.

(18) The compression molded tooth may contain other powders such as a powder of inorganic materials and/or organic materials other than the saccharide powder, polysaccharide powder, protein powder, and/or glycoprotein powder. In this case, the saccharide powder, polysaccharide powder, protein powder, and/or glycoprotein powder acts also as a binder to bond other powders.

(19) The powder of inorganic materials may be a powder, for example, typified by glass powder, ceramic powder, and the like. The powder of organic materials may be, for example, a resin powder. The powder of these inorganic materials and/or organic materials preferably has an average particle size of 0.1 to 30 m, preferably 1 to 15 m.

(20) A dye and/or a pigment is preferably added to these materials as a colorant to thereby color these materials in tooth color such as ivory color.

(21) Compression molding is a technique of compressing a material to thereby mold the same. In the present invention, the compression molding specifically includes preparing a negative mold of a target shape as a mold, filling the negative mold with a predetermined powder material, and applying pressure to the powder material from a predetermined direction to thereby mold the powder material. Further, after applying a predetermined pressure, the negative mold is further filled with a powder material, and pressure is applied to the powder material from a predetermined direction, thereby capable of molding the powder in layers. Variations in cuttability caused by variations in compression can be reduced by repeating molding. If a thick molded article is prepared by one-time compression molding without dividing the compression molding into a plurality of number of times, variations in compression may occur. It is preferred to mold a molded article having a thickness of 2 to 5 mm. Only the crown portion in which an abutment tooth and a cavity are formed is a portion in which such variations in cuttability must be removed. Since it is Satis-factory even if a root portion has variations in cuttability, one-time molding can be adopted.

(22) As a procedure of compression molding, it is preferred to mold the first portion constituting the enamel tooth portion first and mold the second portion constituting the dentin tooth portion later. It is preferred to mold the crown contour of the enamel tooth portion and then advance the molding toward the dentin and root side.

(23) The compression molded tooth preferably has a third portion which is different from the first portion constituting the enamel tooth portion and the second portion constituting the dentin tooth portion.

(24) The third portion may be a portion that constitutes a dental caries portion, a dental pulp portion, and/or a cutting target portion, and when the third portion constitutes any of these portions, it can be prepared in the same manner.

(25) The third portion can be prepared by a method in which materials colored with a colorant are laminated to prepare a layered material for the third portion, and when a compression molded tooth is molded, the layered material is contained inside the tooth. (First preparation method) The materials can be colored with a dye, a pigment, a fluorescent material, and the like.

(26) The third portion can also be prepared by a method in which the layered material for the third portion described above is preliminarily molded to prepare a preliminarily-molded layered member for the third portion, and when the compression molded tooth is molded, the preliminarily-molded layered member for the third portion is contained inside the tooth. (Second preparation method)

(27) Alternatively, the third portion can also be prepared by a method in which a resin layer member for the third portion is prepared beforehand from a resin, and when the compression molded tooth is molded, the resin layer member for the third portion is contained inside the tooth. A silicone resin and an organic polymer can be used as the resin. (Third preparation method)

(28) A preferred method when the third portion constitutes a dental caries portion or a cutting target portion is the first preparation method and the second preparation method. Cuttability can be varied closer to the cuttability of a natural tooth by changing the composition and the like.

(29) A preferred method when the third portion constitutes a dental pulp portion is the third preparation method. The feeling of the dental pulp exposure becomes close to the cuttability of a natural tooth by preparing the pulp from a resin.

(30) Dental college students use a tooth for a jaw tooth model for the practice of abutment tooth preparation and cavity preparation. The technique cannot be mastered by several times of practice, but many teeth are consumed for mastering the technique. Since a tooth made of a resin has been mainly used, incineration or the like has been a main method for waste disposal, which is not environmentally friendly. Since saccharides, polysaccharides, proteins, and/or glycoproteins are used in the present invention, the waste can be used as animal feed or can undergo microbial degradation, which is environmentally friendly.

(31) Further, since the molding method of a tooth is compression molding, the consumption of energy is small in production, and the tooth can be easily produced in simple facilities. Furthermore, cutting feeling can be changed in a tooth, and since cutting feeling is closer to that of a natural tooth than before, the practice close to treatment can be performed.

(32) Since dental college students perform cutting operation, dust is scattered and often sucked by the students. Therefore, it has been required to prepare a tooth from a safer material. In the present invention, a tooth can be prepared from saccharides and polysaccharide, and a safer tooth can be supplied.

(33) Further, in the abutment tooth preparation and cavity preparation in dental treatment, the preparation must be performed so that the dental pulp exposure may not occur during the formation, but such a feeling has not been able to be experienced by a conventional tooth for a jaw tooth model. In the present invention, since the portion of a dental pulp can be formed in the tooth, it is possible to tell the dental pulp exposure.

(34) Further, in the present invention, since not only the dental pulp but also the dental caries can be formed, experience of dental treatment in more accordance with reality can be experienced by the tooth for a jaw tooth model of the present invention.

(35) Furthermore, initial practice does not show how much cutting should be performed for abutment tooth preparation and cavity preparation. In the present invention, a mark of how much cutting should be performed can be put on a target portion, and practice can be performed while checking the progress of cutting.

(36) When an artificial tooth having a hard outside and soft inside is required, the artificial tooth can be prepared by one-time molding according to Method for Preparing Artificial Tooth 1-1 to be described below. The portion of the tooth in the vicinity of a molding die is hard. Further, when an artificial tooth having a uniform cutting feeling through the inner part is required, it can be achieved by successive lamination to a thickness from 1 to 2 mm according to Method for Preparing Artificial Tooth 1-2 to be described below.

EXAMPLES

(37) Hereinafter, the present invention will be described with reference to Examples. However, the present invention is not limited to Examples. First, a specific method for preparing a compression molded tooth in Examples will be described.

(38) (Formulation of Composition)

(39) The details such as components used in Examples are as follows. Xylitol: manufactured by NICHIGA, powder, 100 m Maltitol: manufactured by NICHIGA, powder, 70 m Starch: manufactured by Nisshin Flour Milling Company, flour (weak flour), 10 m Powdered milk: manufactured by Meiji Dairies Corporation, powdered skim milk, 30 m Silica powder (5 m): manufactured by Tokuyama Corporation, silica powder Carbon black: manufactured by Mitsubishi Chemical Corporation, high-class color (HCF) #2650 Red pigment (iron red): manufactured by MORISHITA BENGARA KOGYO CO., LTD., (10 m) Fluorescent material: fluorescent pigment (LUMILUX C-Pigments is an ultraviolet (UV) excitation type organic/inorganic fluorescent pigment) Resin in dental pulp composition: manufactured by SHOFU, INC., Color Toning Wax Red (formed into a dental pulp shape beforehand) Silicone in dental pulp composition: manufactured by SHOFU, INC., Lab Silicone, colored to red with iron red (formed into a dental pulp shape beforehand).

(40) These components were mixed in composition ratios (mass ratio) shown in Table 1 to obtain composition raw materials each having a composition name shown in Table 1.

(41) Next, the composition raw materials each having a composition name shown in Table 1 were used to prepare artificial teeth shown in Table 2. The preparation method is shown below.

(42) (Method for Preparing Artificial Tooth 1-1)

(43) A method for preparing an artificial tooth shown in FIG. 1 will be described. FIG. 1 is a view of an artificial tooth in which an enamel tooth portion 4, a dentin tooth portion 5, and a root tooth portion 8 in the artificial tooth were molded from the same composition raw material at the same time.

(44) The artificial tooth of FIG. 1 is prepared using the mold shown in FIG. 2.

(45) A method for preparing the mold of FIG. 2 and a method for preparing an artificial tooth using the mold of FIG. 2 will be described below. Step 1: A bottom mold 1 of a concave mold which is a split mold divided at the widest contour portion with the labial surface of the artificial tooth facing downward is prepared. The bottom mold 1 of the concave mold is preferably provided with a pushing structure for removing the artificial tooth. Step 2: Next, a side mold 2 of the concave mold is set as a sheath in which a composition raw material is put and as a receiver of a pressing mold. The side mold 2 of the concave mold is preferably prepared such that the side mold is formed along the widest contour portion of the bottom mold 1 of the concave mold; the side mold is provided with a taper of 1 to 10; and as a result, the pressing mold can be easily inserted. Step 3: Next, a convex mold 3 is prepared along the side mold 2 of the concave mold. The convex mold 3 is prepared so that a space for an artificial tooth may be formed when the convex mold is combined with the bottom mold 1 of the concave mold. Step 4: The side mold 2 of the concave mold is set to the bottom mold 1 of the concave mold; a predetermined amount of a composition raw material is charged into a recess; and the convex mold 3 is inserted into the recess so that the composition raw material may be sandwiched. The composition raw material was compression molded by pressurizing (molding pressure is described in Table 2) with a compressor to obtain the artificial tooth.
(Method for Preparing Artificial Tooth 1-2)

(46) Further, another method for preparing an artificial tooth will be described below.

(47) In order to mold an artificial tooth for each layer having a thickness of 1 to 2 mm, a plurality of convex molds 3 are prepared in Step 3 of the above (Method for Preparing Artificial Tooth 1-1). A composition raw material was filled for each layer and successively pressurized with a compressor using the plurality of convex molds 3 (molding pressure is described in Table 2) to thereby obtain the artificial tooth.

(48) An artificial tooth can be molded in the same manner also from the direction shown in FIG. 3. However, since the molding direction is changed, the contour of the bottom mold 1 of the concave mold and the side mold 2 of the concave mold are changed, and the convex mold 3 is a fourth convex mold 3-4. FIG. 3 (A) is a conceptual diagram in which the side mold 2 of the concave mold is set to the bottom mold 1 of the concave mold before inserting the convex mold 3 (fourth convex mold 3-4), and FIG. 3 (B) is a conceptual diagram in which the convex mold 3 (fourth convex mold 3-4) of FIG. 3 (A) is inserted.

(49) An artificial tooth molded from the same composition raw material is more preferably molded by a method of molding an artificial tooth from the molding direction of FIG. 2 as compared with a method of molding an artificial tooth from the molding direction of FIG. 3. Pressure is uniformly applied to the whole artificial tooth to provide better moldability.

(50) Ten artificial teeth were respectively molded from the compositions and under the molding conditions shown in Examples 1 to 10 using the molds of FIG. 2 and FIG. 3 by the above two types of methods (Method for Preparing Artificial Tooth 1-1) and (Method for Preparing Artificial Tooth 1-2). It was verified that the artificial teeth could be molded satisfactorily. Each composition raw material and molding condition are described in Table 2.

(51) (Method for Preparing Artificial Tooth 2-1)

(52) The method for preparing an artificial tooth shown in FIG. 4 will be described. FIG. 4 is a view of an artificial tooth in which the dentin tooth portion 5 and the root tooth portion 8 were molded from the same composition raw material and under the same molding conditions, and the enamel tooth portion 4 was molded from a different composition raw material and/or under different molding conditions, in the artificial tooth.

(53) This is a method for preparing an artificial tooth for reproducing a change of the cutting feeling, particularly, in the case of moving from the enamel tooth portion to the dentin tooth portion, for the purpose of obtaining a cutting feeling of the enamel tooth portion and a cutting feeling of the dentin tooth portion, respectively.

(54) The artificial tooth of FIG. 4 is prepared using the mold shown in FIG. 5.

(55) A method for preparing the mold of FIG. 4 and a method for preparing an artificial tooth using the mold of FIG. 4 will be described below. Step 1: A bottom mold 1 of a concave mold which is a split mold divided at the widest contour portion with the occlusal surface of the artificial tooth facing downward is prepared. The bottom mold 1 of the concave mold is preferably provided with a pushing structure for removing the artificial tooth. Step 2: A side mold 2 of the concave mold is set as a sheath in which a composition raw material is put and as a receiver of a pressing mold. The side mold 2 of the concave mold is preferably prepared such that the side mold is formed along the widest contour portion of the bottom mold 1 of the concave mold; the side mold is provided with a taper of 1 to 10; and as a result, the pressing mold can be easily inserted. Step 3: A convex mold 3 (third convex mold 3-1) for molding the enamel tooth portion is prepared. The third convex mold 3-1 is prepared along the side mold 2 of the concave mold so that a space for the enamel tooth portion may be formed when the convex mold is combined with the bottom mold 1 and the side mold 2 of the concave mold (FIG. 5 (B)). Step 4: A fourth convex mold 3-4 for molding the dentin tooth portion 5 and the root tooth portion 8 is prepared. The fourth convex mold 3-4 is prepared along the side mold 2 of the concave mold so that a space for the artificial tooth may be formed when the convex mold is combined with the bottom mold 1 and the side mold 2 of the concave mold (FIG. 5 (D)). Step 5: The side mold 2 of the concave mold is set to the bottom mold 1 of the concave mold (FIG. 5 (A)); a predetermined amount of a composition raw material suitable for the enamel tooth portion is charged into a recess; and the first convex mold 3-1 is inserted into the recess so that the composition raw material may be sandwiched (FIG. 5 (A) and (B)). The composition raw material was compression molded by pressurizing (molding pressure is described in Table 2) with a compressor to obtain the enamel tooth portion. Step 6: A predetermined amount of a composition raw material suitable for the dentin tooth portion and the root tooth portion is charged into a recess; and the fourth convex mold 3-4 is inserted into the recess so that the composition raw material may be sandwiched (FIG. 5 (C) and (D)). The composition raw material was compression molded by pressurizing (molding pressure is described in Table 2) with a compressor to obtain the artificial tooth.
(Method for Preparing Artificial Tooth 2-2)

(56) Further, another method for preparing an artificial tooth will be described below.

(57) In order to mold an artificial tooth for each layer having a thickness of 1 to 2 mm, a plurality of convex molds 3 are prepared in Steps 3 and 4 of the above (Method for Preparing Artificial Tooth 2-1). A composition raw material was filled for each layer and successively pressurized with a compressor using the plurality of convex molds 3 (molding pressure is described in Table 2) to thereby obtain the artificial tooth.

(58) Ten artificial teeth were respectively molded from the compositions and under the molding conditions shown in Examples 11 to 19 using the mold of FIG. 5 by the above two types of methods (Method for Preparing Artificial Tooth 2-1) and (Method for Preparing Artificial Tooth 2-2). It was verified that the artificial teeth could be molded satisfactorily. Each composition raw material and molding condition are described in Table 2.

(59) (Method for Preparing Artificial Tooth 3-1)

(60) The method for preparing an artificial tooth shown in FIG. 6 will be described. FIG. 6 is a view of an artificial tooth in which the enamel tooth portion 4, the dentin tooth portion 5, the root tooth portion 8, and a third portion (layer (dental pulp)) 6 in the artificial tooth were respectively prepared from the same or different composition raw material and/or under different molding conditions.

(61) This is a method for preparing an artificial tooth for the purpose of obtaining a cutting feeling of the enamel tooth portion and a cutting feeling of the dentin tooth portion, respectively, and further for the purpose of reproducing a change of the cutting feeling in the case of moving from the dentin tooth portion to the layer of the third portion, the dental pulp 6.

(62) The artificial tooth of FIG. 6 is prepared using the mold shown in FIG. 7.

(63) A method for preparing the mold of FIG. 7 and a method for preparing an artificial tooth using the mold of FIG. 7 will be described below. Step 1: A bottom mold 1 of a concave mold which is a split mold divided at the widest contour portion with the occlusal surface of the artificial tooth facing downward is prepared. The bottom mold 1 of the concave mold is preferably provided with a pushing structure for removing the artificial tooth. Step 2: A side mold 2 of the concave mold is set as a sheath in which a composition raw material is put and as a receiver of a pressing mold (FIG. 7 (A)). The side mold 2 of the concave mold is preferably prepared such that the side mold is formed along the widest contour portion of the bottom mold 1 of the concave mold; the side mold is provided with a taper of 1 to 10; and as a result, the pressing mold can be easily inserted. Step 3: A convex mold 1 (first convex mold 3-1) for molding the enamel tooth portion 4 is prepared. The first convex mold 3-1 is prepared along the side mold 2 of the concave mold so that a space for the enamel tooth portion may be formed when the convex mold is combined with the bottom mold 1 and the side mold 2 of the concave mold (FIG. 7 (B)). Step 4: A convex mold 3 (second convex mold 3-2) for molding the dentin tooth portion 5 is prepared. The second convex mold 3-2 is prepared along the side mold 2 of the concave mold so that a space for the dentin tooth portion may be formed when the convex mold is combined with the bottom mold 1 and the side mold 2 of the concave mold (FIG. 7 (D)). Step 5: A convex mold 3 (third convex mold 3-3) for molding the dental pulp portion 6 is prepared. The third convex mold 3-3 is prepared along the side mold 2 of the concave mold so that a space for the dental pulp portion 6 may be formed when the convex mold is combined with the bottom mold 1 and the side mold 2 of the concave mold (FIG. 7 (F)). Step 6: A convex mold 3 (fourth convex mold 3-4) for molding the root tooth portion 8 is prepared. The fourth convex mold 3-4 is prepared along the side mold 2 of the concave mold so that a space for the artificial tooth may be formed when the convex mold is combined with the bottom mold 1 and the side mold 2 of the concave mold (FIG. 7 (H)). Step 7: The side mold 2 of the concave mold is set to the bottom mold 1 of the concave mold (FIG. 7 (A)); a predetermined amount of a composition raw material suitable for the enamel portion is charged into a recess; and the first convex mold 3-1 is inserted into the recess so that the composition raw material may be sandwiched (FIG. 7 (A) and (B)). The composition raw material was compression molded by pressurizing (molding pressure is described in Table 2) with a compressor to obtain the enamel tooth portion. Step 8: A predetermined amount of a composition raw material suitable for the dentin portion is charged into a recess, and the second convex mold 3-2 is inserted into the recess so that the composition raw material may be sandwiched (FIG. 7 (C) and (D)). The composition raw material was compression molded by pressurizing (molding pressure is described in Table 2) with a compressor to obtain the dentin tooth portion. Step 9: A predetermined amount of a composition raw material suitable for the dental pulp portion is charged into a recess, and the third convex mold 3-3 is inserted into the recess so that the composition raw material may be sandwiched (FIG. 7 (E) and (F)). The composition raw material was compression molded by pressurizing (molding pressure is described in Table 2) with a compressor to obtain the dental pulp portion 6. Step 10: A predetermined amount of a composition raw material suitable for the root portion is charged into a recess, and the fourth convex mold 3-4 is inserted into the recess so that the composition raw material may be sandwiched (FIG. 7 (G) and (H)). The composition raw material was compression molded by pressurizing (molding pressure is described in Table 2) with a compressor to obtain the artificial tooth.

(64) Although a composition raw material suitable for the dental pulp portion is charged in Step 9, it is possible to produce an artificial tooth by inserting a member, which has been preliminarily molded to a dental pulp shape, into the dental pulp portion. A preliminarily molded member made of an acrylic resin and a preliminarily molded member made of silicone were used in Example 30 and Example 31, respectively.

(65) (Method for Preparing Artificial Tooth 3-2)

(66) Further, another method for preparing an artificial tooth will be described below.

(67) In order to mold an artificial tooth for each layer having a thickness of 1 to 2 mm, a plurality of convex molds 3 are prepared in Steps 3, 4, 5, and 6 of the above (Method for Preparing Artificial Tooth 3-1). A composition raw material was filled for each layer and successively pressurized with a compressor using the plurality of convex molds 3 (molding pressure is described in Table 2) to thereby obtain the artificial tooth.

(68) Ten artificial teeth were respectively molded from the compositions and under the molding conditions shown in Examples 20 to 31 using the mold of FIG. 7 by the above two types of methods (Method for Preparing Artificial Tooth 3-1) and (Method for Preparing Artificial Tooth 3-2). It was verified that the artificial teeth could be molded satisfactorily. Each composition raw material and molding condition are described in Table 2.

(69) The dental pulp in Examples was also produced by preliminarily molding and inserting it into the dental pulp portion.

(70) (Method for Preparing Artificial Tooth 4-1)

(71) A plurality of convex molds were used in the same manner as in (Method for Preparing Artificial Tooth 3-1) to prepare an artificial tooth having the dental caries shown in FIG. 8.

(72) Ten artificial teeth were respectively molded from the compositions and under the molding conditions shown in Examples 32 to 41 by the above method (Method for Preparing Artificial Tooth 4-1). It was verified that the artificial teeth could be molded satisfactorily. Each composition raw material and molding condition are described in Table 2.

(73) TABLE-US-00001 TABLE 1 Composition name 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Xylitol 100 50 10 95 90 80 29 29 Maltitol 100 50 Starch 100 50 40 67 67 Powdered milk 100 50 50 49 49 Silica powder (30 m) 5 10 20 70 30 50 70 30 50 Carbon black 1 1 1 Red pigment (iron red) 1 1 1 (% by mass)

(74) TABLE-US-00002 TABLE 2 Example Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 10 Enamel 1 2 3 4 5 6 7 8 9 10 composition Dentin/root 1 2 3 4 5 6 7 8 9 10 composition Enamel molding 20 90 20 80 40 60 60 60 60 60 pressure (MPa) Dentin/root 20 90 20 80 40 60 60 60 60 60 molding pressure (MPa) Moldability Satis- Satis- Satis- Satis- Satis- Satis- Satis- Satis- Satis- Satis- factory factory factory factory factory factory factory factory factory factory Example Example Example Example Example Example Example Example Example 11 12 13 14 15 16 17 18 19 Enamel 1 1 1 2 2 2 2 2 2 composition Dentin/root 1 1 1 3 3 3 9 10 10 composition Enamel molding 60 80 90 60 80 90 60 80 90 pressure (MPa) Dentin/root 10 50 70 10 50 70 10 50 70 molding pressure (MPa) Moldability Satis- Satis- Satis- Satis- Satisfactory Satisfactory Satisfactory Satisfactory Satisfactory factory factory factory factory Example Example Example Example Example Example Example Example Example Example 20 21 22 23 24 25 26 27 28 29 Enamel 1 1 1 1 1 1 3 4 1 1 composition Dentin/root 1 1 1 1 1 1 3 4 4 10 composition Dental pulp 14 15 16 14 15 16 14 15 16 14 composition Enamel molding 60 60 60 60 60 60 60 60 60 60 pressure (MPa) Dentin/root 60 60 60 20 20 20 20 20 20 20 molding pressure (MPa) Dental pulp 60 60 60 10 10 10 10 10 10 10 molding pressure (MPa) Moldability Satis- Satis- Satis- Satis- Satis- Satis- Satis- Satis- Satis- Satis- factory factory factory factory factory factory factory factory factory factory Example Example 30 31 Enamel 1 1 composition Dentin/root 1 1 composition Dental pulp Resin Silicone composition Enamel molding 60 60 pressure (MPa) Dentin/root 20 20 molding pressure (MPa) Dental pulp 10 10 molding pressure (MPa) Moldability Satisfactory Satisfactory Example Example Example Example Example Example Example Example Example Example 32 33 34 35 36 37 38 39 40 41 Enamel 1 1 1 1 1 1 3 4 1 1 composition Dentin/root 1 1 1 1 1 1 3 4 4 10 composition Dental caries 11 12 13 11 12 13 11 12 13 11 composition Enamel molding 60 60 60 60 60 60 60 60 60 60 pressure (MPa) Dentin/root 60 60 60 20 20 20 20 20 20 20 molding pressure (MPa) Dental caries 60 60 60 10 10 10 10 10 10 10 molding pressure (MPa) Moldability Satis- Satis- Satis- Satis- Satis- Satis- Satis- Satis- Satis- Satis- factory factory factory factory factory factory factory factory factory factory

(75) The following effects were confirmed from each Example. The same composition is used for the composition of the enamel portion, the composition of the dentin portion, and the composition of the root portion. Thereby, the control of raw materials is easy and preferred. Cuttability was able to be changed by changing the molding pressure of the enamel portion and the dentin portion while using the same raw materials. It is important to obtain a cutting feeling of the enamel portion and the dentin portion. When five dentists evaluated the cuttability of artificial teeth prepared in Examples 1 to 19, the result was that the artificial teeth of Examples 11 to 19 were similar to a natural teeth. By using silica powder in the composition, a cutting feeling became flexible, and the same cutting feeling as that of the dentin portion was able to be obtained. Since the dental pulp portion is colored, the dental pulp exposure is easily found. The dental pulp exposure can be felt by using a resin and silicone for the dental pulp portion.

INDUSTRIAL APPLICABILITY

(76) The present invention provides a tooth for a jaw tooth model for a dental college student to practice cavity preparation and abutment tooth preparation which are therapeutic actions, and the tooth can be utilized for industry.