DENTAL MOLDED ARTICLE AND DENTAL RESIN MATERIAL

Abstract

A dental molded article has a predetermined shape so as to be used in an oral cavity, and contains polycaprolactone, acrylic resin, powdery silica, ascorbic acid, titanium oxide, a pigment, and zinc stearate. The acrylic resin is set to have a weight ratio of 5 to 30%, the powdery silica is set to have a weight ratio of 5 to 25%, the ascorbic acid is set to have a weight ratio of 0.3 to 1.8%, the titanium oxide is set to have a weight ratio of 0.001 to 0.02%, the pigment is set to have a weight ratio of 0.001 to 0.1%, and the zinc stearate is set to have a weight ratio of 0.001 to 0.1%, with respect to the polycaprolactone. Thus, a dental molded article and a dental resin material that can easily fit a mucosal surface in an oral cavity of a patient, are provided.

Claims

1. A dental molded article that has a predetermined shape, that is used in an oral cavity, and that contains polycaprolactone, the dental molded article comprising: acrylic resin made of a polymer of acrylic acid ester, a polymer of methacrylic acid ester, or a copolymer of acrylic acid ester and methacrylic acid ester, the acrylic resin having a weight ratio of 5 to 30% with respect to the polycaprolactone; powdery silica having a weight ratio of 5 to 25% with respect to the polycaprolactone; ascorbic acid having a weight ratio of 0.3 to 1.8% with respect to the polycaprolactone; titanium oxide having a weight ratio of 0.001 to 0.02% with respect to the polycaprolactone; a pigment having a weight ratio of 0.001 to 0.1% with respect to the polycaprolactone; zinc stearate having a weight ratio of 0.001 to 0.1% with respect to the polycaprolactone; and a remainder being the polycaprolactone and unavoidable impurities.

2. (canceled)

3. A dental molded article that has a predetermined shape, that is used in an oral cavity, and that contains polycaprolactone, the dental molded article comprising: thermoplastic polyester resin having a weight ratio of 5 to 30% with respect to the polycaprolactone; powdery silica having a weight ratio of 5 to 25% with respect to the polycaprolactone; ascorbic acid having a weight ratio of 0.3 to 1.8% with respect to the polycaprolactone; titanium oxide having a weight ratio of 0.001 to 0.02% with respect to the polycaprolactone; a pigment having a weight ratio of 0.001 to 0.1% with respect to the polycaprolactone; zinc stearate having a weight ratio of 0.001 to 0.1% with respect to the polycaprolactone; and a remainder being the polycaprolactone and unavoidable impurities.

4. (canceled)

5. A dental resin material that is used in accordance with a dental molded article used in an oral cavity, and that contains polycaprolactone, the dental resin material comprising: acrylic resin made of a polymer of acrylic acid ester, a polymer of methacrylic acid ester, or a copolymer of acrylic acid ester and methacrylic acid ester, the acrylic resin having a weight ratio of 5 to 30% with respect to the polycaprolactone; powdery silica having a weight ratio of 5 to 25% with respect to the polycaprolactone; and a remainder being the polycaprolactone and unavoidable impurities.

6. (canceled)

7. A dental resin material that is used in accordance with a dental molded article used in an oral cavity, and that contains polycaprolactone, the dental resin material comprising: thermoplastic polyester resin having a weight ratio of 5 to 30% with respect to the polycaprolactone; powdery silica having a weight ratio of 5 to 25% with respect to the polycaprolactone; and a remainder being the polycaprolactone and unavoidable impurities.

8. (canceled)

9. The dental molded article according to claim 1, wherein the acrylic resin has a weight ratio of 10 to 25% with respect to the polycaprolactone, and the powdery silica has a weight ratio of 5 to 20% with respect to the polycaprolactone.

10. The dental molded article according to claim 3, wherein the thermoplastic polyester resin has a weight ratio of 10 to 25% with respect to the polycaprolactone, and the powdery silica has a weight ratio of 5 to 20% with respect to the polycaprolactone.

11. The dental resin material according to claim 5, wherein the acrylic resin has a weight ratio of 10 to 25% with respect to the polycaprolactone, and the powdery silica has a weight ratio of 5 to 20% with respect to the polycaprolactone.

12. The dental resin material according to claim 7, wherein the thermoplastic polyester resin has a weight ratio of 10 to 25% with respect to the polycaprolactone, and the powdery silica has a weight ratio of 5 to 20% with respect to the polycaprolactone.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1 illustrates a partial denture as a dental molded article according to this invention.

[0048] FIG. 2 illustrates an example in which the partial denture shown in FIG. 1 is placed in a human oral cavity.

[0049] FIG. 3 illustrates a crown representing an example of a dental prosthesis as the dental molded article according to this invention.

[0050] FIG. 4 illustrates an aesthetic laminate representing an example of a dental prosthesis as the dental molded article according to this invention.

[0051] FIG. 5 illustrates an example in which the aesthetic laminate shown in FIG. 4 is placed over a human anterior tooth.

[0052] FIG. 6 illustrates an example of an orthodontic appliance as the dental molded article according to this invention.

[0053] FIG. 7 illustrates an example in which the orthodontic appliance shown in FIG. 6 is placed in a human oral cavity.

[0054] FIG. 8 illustrates a mouthpiece representing an example of a dental temporary crown as the dental molded article according to this invention.

[0055] FIG. 9 illustrates an example in which a denture base repairing material as a dental resin material according to this invention is used.

[0056] FIG. 10 illustrates an example in which a denture base stabilizer as the dental resin material according to this invention is used.

[0057] FIG. 11 illustrates an example in which a denture base stabilizer as the dental resin material according to this invention is used.

DESCRIPTION OF EMBODIMENTS

[0058] FIG. 1 to FIG. 8 each illustrate an example of a dental molded article according to this invention. FIG. 1 illustrates an example of a denture base 1a of a partial denture 1 (reference character 1b represents an artificial tooth). FIG. 2 illustrates an example in which the partial denture 1 is placed in a human oral cavity. FIG. 3 illustrates an example of a crown 2 (dental prosthesis). FIG. 4 illustrates an example of an aesthetic laminate 3 (dental prosthesis). FIG. 5 illustrates an example in which the aesthetic laminate 3 is placed over a human anterior tooth. FIG. 6 illustrates an example of an orthodontic appliance 4. FIG. 7 illustrates an example in which the orthodontic appliance 4 is placed in a human oral cavity. FIG. 8 illustrates an example of a mouthpiece (dental temporary crown).

[0059] FIG. 9 to FIG. 11 each illustrate an example of a dental resin material according to this invention. FIG. 9 illustrates an example in which a denture base repairing material 6a is used (reference character 6 represents full dentures). FIG. 10 illustrates an example of the full dentures 6 for which a denture base stabilizer 6b is placed. FIG. 11 also illustrates an example of full dentures 7 for which the denture base stabilizer 6b is placed.

[0060] Next, examples of the dental resin material for producing such various kinds of the dental molded articles will be described.

Example 1

[0061] Firstly, an unpolymerized acrylic monomer, for example, MMA was polymerized with a polymer of methacrylic acid ester, for example, PMMA which had a weight ratio of 70%, to obtain acrylic resin (containing unavoidable impurities). Instead of the methacrylic acid ester, acrylic acid ester may be used. Alternatively, a copolymer of acrylic acid ester and methacrylic acid ester may be used.

[0062] Next, polycaprolactone (PCL) obtained by synthesis of -caprolactone ([C6H10O2] (2-oxepanone homopolymer), and the acrylic resin having a weight ratio of 15% with respect to the polycaprolactone (PCL) were further copolymerized with each other to generate copolymerized polycaprolactone. Adjustment was performed in the obtained copolymerized polycaprolactone such that the weight ratio of ascorbic acid was 0.8%, the weight ratio of titanium oxide was 0.009%, the weight ratio of a red pigment (for example, one or more selected from organic and inorganic pigments such as aluminum lake and red iron oxide, which are certified colorants) was 0.003%, and the weight ratio of zinc stearate was 0.018%, with respect to the polycaprolactone (PCL).

[0063] Specifically, for use in a denture base gum part, the weight ratio of the acrylic resin is 20% (10 kg), the weight ratio of powdery silica is 15% (7.5 kg), the weight ratio of ascorbic acid is 0.8% (400 g), the weight ratio of titanium oxide is 0.009% (4.5 g), the weight ratio of the red pigment is 0.003% (1.5 g), and the weight ratio of zinc stearate is 0.018% (9 g), with respect to polycaprolactone (PCL) (50 kg).

[0064] The above-described materials (copolymerized polycaprolactone, ascorbic acid, titanium oxide, the red pigment, and zinc stearate) were blended by an extruder, and a colored pellet-like dental resin material (dental resin material used for producing the dental molded article substituting for gums and the like) was obtained. The dental resin material contains a very small amount of unavoidable impurities as a weight ratio with respect to the polycaprolactone. They have no relation with the intrinsic requirements and effects of this invention, and do not exert an influence thereon.

[0065] The dental molded articles such as the denture base 1a, the crown 2 (dental prosthesis), the aesthetic laminate 3 (dental prosthesis), the orthodontic appliance 4, and the mouthpiece 5 (dental temporary crown) as shown in FIG. 1 to FIG. 8 are obtained through molding from the generated dental resin material. In a case where such a dental molded article is molded, processing can be easily performed by using a typical general-purpose molding machine through any of injection molding, compression molding, vacuum pressure molding, and the like. The denture base 1a and the artificial tooth 1b shown in FIG. 1 are chemically bonded to each other by using a solvent, whereby food residue can be inhibited from entering a boundary between the denture base 1a and the artificial tooth 1b and remaining therebetween, thereby suppressing proliferation of bacteria.

[0066] In a case where the dental molded article according to this invention is produced by injection molding, for example, the dental resin material in pellet form is put into a barrel of a general-purpose resin molding machine, and the furnace temperature is set to 70 to 100 C. to soften and melt the raw material, thereby performing the injection molding. The dental resin material has zinc stearate blended therein and thus has high resin fluidity, and can allow the molded article to precisely exhibit reproducibility in detail.

[0067] The above-described dental resin material can be used as the denture base repairing material 6a, and the denture base stabilizers 6b, 6b as shown in FIG. 9 to FIG. 11, respectively. In this case, the dental resin material need not be formed into a specific shape, and may be formed into, for example, a quadrangular-plate-like shape, softened when used, and attached to the full dentures 6, 7.

[0068] The dental molded article and the dental resin material as described above have the following substantially advantageous characteristics and features.

[0069] 1. Resin allergy reaction is not caused in human bodies.

[0070] 2. Bisphenol A as a material that causes an endocrine disrupting action is not eluted, so that the dental molded article and the like can be used for human bodies with high safety.

[0071] 3. The resin components are not eluted in an oral cavity with respect to all the additives, and, therefore, high safety can be provided and there is no safety concern about the additives and the pigments.

[0072] 4. A polyester fiber material that is colored so as to simulate blood vessels in human oral cavities may be embedded in the molded article, for aesthetically increasing the naturalness of the denture base.

[0073] 5. By blending zinc stearate as an additive, the pigments are completely and uniformly mixed during dyeing of resin, to substantially enhance dyeability.

[0074] 6. By blending zinc stearate, lubrication of the surface of the resin itself increases, thereby increasing smoothness. This is effective for attaching and detaching the denture base body.

[0075] 7. By blending titanium oxide as an additive, a natural hue can be reproduced so as to match human gums during dyeing of the denture base.

[0076] 8. The dental molded article according to this invention has a mechanical strength, a bending strength, and heat resistance that are more excellent than or equivalent to those of a dental molded resin material (polycarbonate, polyamide, nylon, acrylic, or the like) that has been conventionally used, so that the denture base can be produced such that the denture base is unlikely to be broken, is very compact, and does not provide an uncomfortable feeling in an oral cavity. Furthermore, water absorption is very low as compared with a conventional resin material, and proliferation of bacteria and deterioration of the physical properties of resin due to water absorption are substantially reduced.

[0077] 9. The dental molded article and the like according to this invention are unlikely to absorb water in air and can be stored at normal temperatures without problem. The dental molded article and the like need not be dried by heat for removing a water content during injection molding, and work efficiency is also excellent.

[0078] 10. The dental molded article and the like according to this invention can be softened at a temperature of about 70 to 75 C. to freely change the shape, and can easily fit the form and structure of a mucosal surface, a tooth cervix, and a molded tooth.

[0079] The evaluation test was performed for the above-described dental molded article (dental molded article substituting for gums and the like) according to this invention, and the results are indicated in Table 1.

TABLE-US-00001 TABLE 1 Example 1 Example 2 polypropylene polyamide polycarbonate molding temperature C. 80~120 80~120 180~220 230~270 270~300 molding shrinkage rate 0.1~0.2 0.08~0.15 0.3~0.4 0.2~0.3 0.1~0.3 attachability good good slightly good slightly good slightly good grinding feeling good good poor poor slightly good removability from plaster good good good good slightly good model flexural modulus Mpa 3600 3800 2150 3500 2500 bending before water whitened when whitened when whitened when broken when broken when absorption bending was bending was bending was bending was bending was performed 250 performed 250 performed 200 performed 120 performed 5 or more times or more times times times times bending after water as above as above as above as above as above absorption bending strength Mpa 150 170 60 65 91 elongation mm not less than 15 not less than 16 not less than 12 not less than 12 not less than 12 hardness Hv 13 13 9.8 9.4 13.3 water absorption rate wt % 0.05~0.2 0.1~0.4 0.04~0.08 0.3~0.8 0.2~0.8 coloring E curry 1.29 1.2 1.25 1.5 1.5 coloring E fuchsin 5 5 5 9 9

[0080] As indicated in Table 1, for example, as to a result of measurement in the repeated-bending tests before and after water absorption, the dental resin material of example 1 was more excellent than other dental resin materials (polyamide and polycarbonate except for polypropylene). For example, in the repeated-bending test before water absorption, although the material made of polycarbonate was broken when the bending test was performed five times, and the material made of polyamide was broken when the bending test was performed 120 times, no fracture and breakage occurred in the product of this invention even when the product was bent 200 times.

[0081] In the repeated-bending test after water absorption, although the material made of polycarbonate was broken when the bending test was performed six times, and the material made of polyamide was broken when the bending test was performed 118 times, no fracture occurred in the product of example 1 even when the bending test was performed 250 times. In the resin material (molded article) of this invention, the bending strength was 150 MPa, the elongation was not less than 15 mm, and the water absorption rate was 0.05 to 0.2 wt %, and very good values were obtained. Furthermore, the experiment results for the workability, coloring, and the like were also good as indicated in Table 1.

[0082] The test for coloring will be described in more detail. The coloring E curry in the second line from the bottom in Table 1 represents, as a numerical value, a result of a test in which a resin piece as a sample was immersed, in hot water in which curry powder was dissolved, at 37 C. for one week, the resin piece as the sample was then taken out, and the degree of coloring by the curry powder solution was examined by using a dedicated testing machine. The less the numerical value is, the less the degree of the coloring is, that is, the less discoloring is. Furthermore, coloring E fuchsin represents a result of a similar test in which fuchsin was used as a colorant instead of the curry powder. The less the numerical value is in the test, the less discoloring is. As is apparent from the results, the value in the test with coloring E curry was 1.29 in example 1, the value in the test with coloring E fuchsin was 5 in example 1, and the values were sufficiently small as compared with the values in the tests for polyamide and polycarbonate, and discoloring is less likely to occur in example 1.

Example 2

[0083] Powdery PET resin was prepared as thermoplastic polyester resin instead of the acrylic resin used in example 1. The PET resin was a commercially available product obtained by polycondensation of terephthalic acid or dimethyl terephthalate, and ethylene glycol. Instead of the PET resin, another commercially available thermoplastic polyester such as PBT resin and PEN resin may be used.

[0084] Polycaprolactone (PCL) obtained by synthesis of -caprolactone ([C6H1002] (2-oxepanone homopolymer), and the PET resin having a weight ratio of 15% with respect to the polycaprolactone (PCL) were copolymerized with each other to generate copolymerized polycaprolactone. Adjustment was performed in the obtained copolymerized polycaprolactone such that the weight ratio of ascorbic acid was 0.8%, the weight ratio of titanium oxide was 0.009%, the weight ratio of a red pigment (for example, one or more selected from organic and inorganic pigments such as aluminum lake and red iron oxide, which are certified colorants) was 0.003%, and the weight ratio of zinc stearate was 0.018%, with respect to the polycaprolactone (PCL).

[0085] Specifically, for use in a denture base gum part, the weight ratio of the PET resin was 20% (10 kg), the weight ratio of powdery silica was 15% (7.5 kg), the weight ratio of ascorbic acid was 0.8% (400 g), the weight ratio of titanium oxide was 0.009% (4.5 g), the weight ratio of the red pigment was 0.003% (1.5 g), and the weight ratio of zinc stearate was 0.018% (9 g), with respect to polycaprolactone (PCL) (50 kg).

[0086] The same evaluation test as in example 1 was performed for the above-described dental molded article (dental molded article substituting for gums or the like) of example 2. The results are indicated in Table 1. As indicated in Table 1, almost the same results as in example 1 were obtained for the dental molded article of example 2.

DESCRIPTION OF THE REFERENCE CHARACTERS

[0087] 1 partial denture [0088] 1a denture base [0089] 2 crown (dental prosthesis) [0090] 3 aesthetic laminate (dental prosthesis) [0091] 4 orthodontic appliance [0092] 5 mouthpiece (dental temporary crown) [0093] 6, 7 full dentures [0094] 6a denture base repairing material [0095] 6b denture base stabilizer