DENTAL POLYMERIZABLE COMPOSITION

Abstract

A dental polymerizable composition including a glass powder and a (meth)acrylate is provided. The glass powder includes zinc, silicon, and fluorine and is substantially free of aluminum.

Claims

1. A dental polymerizable composition comprising: a glass powder and a (meth)acrylate; wherein the glass powder includes zinc, silicon, and fluorine and is substantially free of aluminum.

Description

EXAMPLES

[0089] In the following, the present invention will be described in further detail with reference to examples and comparative examples. Note, however, that the present invention is not limited to these examples.

Examples 1 to 14

[0090] [Production of Glass Powder]

[0091] In each example, zinc oxide (ZnO), anhydrous silicic acid (SiO.sub.2), calcium fluoride (CaF.sub.2), calcium phosphate (Ca.sub.3(PO.sub.4).sub.2), strontium fluoride (SrF.sub.2), phosphorus oxide (P.sub.2O.sub.5), lanthanum oxide (La.sub.2O.sub.3), sodium fluoride (NaF), and potassium hydrogencarbonate (KHCO.sub.3) were combined at a predetermined ratio and were sufficiently mixed and agitated using a mortar. The obtained mixture was then placed in a platinum crucible and placed in an electric furnace. The electric furnace was heated to 1300 C. to cause the mixture to melt and be sufficiently homogenized, and thereafter, the mixture was poured into water to form a lump of glass. The obtained lump of glass was subjected to dry pulverization for 20 hours using a ball mill made of alumina and then passed through a 120 mesh sieve. Further, wet pulverization was carried out for 66 hours using a ball mill made of alumina to obtain a glass powder.

[0092] Then, the number average particle diameter and composition of the glass powder were evaluated.

[0093] <Particle Diameter of Glass Powder>

[0094] The particle size distribution of the glass powder was measured using a laser diffraction particle size analyzer LA-950 (manufactured by Horiba Ltd.).

[0095] Tables 1 and 2 indicate the number average particle diameter of the glass powder obtained by the above measurement.

[0096] <Composition of Glass Powder>

[0097] The glass powder was analyzed using a fluorescent X-ray analyzer ZSX Primus II (manufactured by Rigaku Corporation) to determine its composition.

[0098] Table 1 indicates the composition of the glass powder (mass %) determined by the above analysis.

[0099] Note that the contents of Zn, Al, Si, Ca, P, Sr, La, Na and K are respectively expressed in terms of the amounts of ZnO, Al.sub.2O.sub.3, SiO.sub.2, CaO, P.sub.2O.sub.5, SrO, La.sub.2O.sub.3, Na.sub.2O, and K.sub.2O in the glass powder.

[0100] Note that although no aluminum compound was added to the raw material compositions of Examples 1 to 13, 0.1 to 0.5 mass % of aluminum in terms of the amount of aluminum oxide (Al.sub.2O.sub.3) was detected in the glass powders. The presence of aluminum in the glass powder may be attributed to alumina derived from an alumina ball or an alumina pot used at the time of pulverization being mixed into the glass powder or a detection error of the fluorescent X-ray analyzer, for example.

[0101] [Production of Adhesive]

[0102] In each example, an adhesive was prepared by mixing the glass powder, a methacrylate, a polymerization initiator, a polymerization accelerator, a polymerization inhibitor, and a filler at the ratio [mass %] indicated in Tables 1A and 1B.

[0103] Note that the adhesive of Example 7 was a two-component type adhesive and was prepared by mixing together a first component and a second component at a ratio of 1:1 (mass %). The adhesives of the examples other than Example 7 were single-component type adhesives.

[0104] Note that the abbreviations in Tables 1A and 1B stand for the following substances.

[0105] (Methacrylate) [0106] HEMA: 2-hydroxyethyl methacrylate [0107] NPG: neopentyl glycol dimethacrylate [0108] 3G: triethylene glycol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) [0109] Bis-GMA: bisphenol A glycidyl methacrylate (2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl]propane) [0110] UDMA: di-2-methacryloyloxyethyl-2,2,4-trimethylhexamethylene dicarbamate [0111] MDP: 10-methacryloyloxydecyl dihydrogen phosphate (Photopolymerization Initiator) [0112] CQ: camphorquinone [0113] TPO: 2,4,6-trimethoxybenzoyl diphenylphosphine oxide (manufactured by BASF)

[0114] (Photopolymerization Accelerator) [0115] EPA: ethyl 4-dimethylaminobenzoate

[0116] (Oxidizing Agent in Chemical Initiator) [0117] BPO: benzoyl peroxide

[0118] (Reducing Agent in Chemical Initiator) [0119] PA: p-tolyldiethanolamine

[0120] (Polymerization Inhibitor) [0121] BHT: Dibutylhydroxytoluene

[0122] (Filler) [0123] Inorganic filler: Aerosil R972 having a number average particle diameter of 0.2 m (manufactured by Nippon Aerosil Co., Ltd.)

Comparative Examples 1 to 7

[0124] [Production of Glass Powder]

[0125] In each comparative example, zinc oxide (ZnO), aluminum oxide (Al.sub.2O.sub.3), aluminum fluoride (AlF.sub.3), anhydrous silicic acid (SiO.sub.2), calcium fluoride (CaF.sub.2), calcium phosphate (Ca.sub.3(PO.sub.4).sub.2), strontium fluoride (SrF.sub.2), phosphorus oxide (P.sub.2O.sub.5), lanthanum oxide (La.sub.2O.sub.3), sodium fluoride (NaF), and potassium hydrogencarbonate (KHCO.sub.3) were combined at a predetermined ratio and were sufficiently mixed and agitated using a mortar. The obtained mixture was then placed in a platinum crucible and placed in an electric furnace. The electric furnace was heated to 1300 C. to cause the mixture to melt and be sufficiently homogenized, and thereafter, the mixture was poured into water to form a lump of glass. The obtained lump of glass was subjected to dry pulverization for 20 hours using a ball mill made of alumina and then passed through a 120 mesh sieve. Further, wet pulverization was carried out for 66 hours using a ball mill made of alumina to obtain a glass powder.

[0126] [Production of Adhesive]

[0127] In each comparative example, an adhesive was prepared by mixing the glass powder, methacrylate, a polymerization initiator, a polymerization accelerator, a polymerization inhibitor, and a filler at the ratio [mass %] indicated in Table 2.

[0128] Note that the adhesives of Comparative Examples 1 to 7 were single-component type adhesives.

[0129] Then, the tooth substance decalcification inhibiting effect and adhesiveness of the adhesives were evaluated.

[0130] <Tooth Substance Decalcification Inhibiting Effect>

[0131] A bonding material, G-Premio Bond (manufactured by GC Corporation), was applied to bovine dentin, after which the bovine dentin was left as is for 10 seconds and then dried with high pressure air for 5 seconds. Then, after applying an adhesive, weak pressure air was used to thinly spread the adhesive. Further, light was irradiated in Mode 20 using a light irradiator, G-Light Prima (manufactured by GC Corporation), to cause setting of the bonding material and the adhesive.

[0132] Then, the bovine dentin having set products of the bonding material and the adhesive formed thereon was immersed in a decalcification liquid (50 mM acetic acid, 1.5 mM calcium chloride, 0.9 mM potassium dihydrogen phosphate, pH 4.5) at 37 C. for 24 hours.

[0133] Then, an image of the bovine dentin having set products of the bonding material and the adhesive formed thereon was captured through x-ray transmission using an X-ray inspection apparatus (CT), and the captured image was analyzed using image processing software to determine the amount of mineral loss and evaluate the tooth substance decalcification inhibiting effect. The categories of the rating scale used for evaluating the tooth substance decalcification inhibiting effect are as follows. [0134] A: amount of mineral loss is less than 3100 volume %.Math.m [0135] B: amount of mineral loss is greater than or equal to 3100 volume %.Math.m and less than 3600 volume %.Math.m [0136] C: amount of mineral loss is greater than or equal to 3600 volume %.Math.m

[0137] Note that bovine dentin that was not coated with a bonding material and an adhesive was subjected to the tooth substance decalcification inhibiting effect evaluation in the same manner as described above except that the bonding material and the adhesive were not applied. As a result, the amount of mineral loss was greater than or equal to 4557 volume %.Math.m.

[0138] [Adhesiveness]

[0139] A crown portion of a bovine lower jaw anterior tooth was embedded in a room temperature polymerizing resin with the labial surface exposed, and then polished using SiC abrasive paper having a particle size of 320 until enamel (or dentin) was exposed.

[0140] The bonding material, G-Premio Bond (manufactured by GC Corporation), was applied to the polished dentin, left as is for 10 seconds, and then dried with high pressure air for 5 seconds. Then, after applying an adhesive, weak pressure air was used to thinly spread the adhesive. Further, a mold (manufactured by ULTRADENT Co., Ltd.) having a hole with a diameter of 2.38 mm was placed on the surface of the dentin coated with the adhesive to define the area of an adherend, and thereafter, light was irradiated in Mode 10 using the light irradiator, G-Light Prima (manufactured by GC Corporation), to cause setting of the bonding material and the adhesive. Then, after filling the mold with Clearfill AP-X (manufactured by Kuraray Co., Ltd.) as a composite resin, light was irradiated in Mode 20 using the light irradiator, G-Light Prima (manufactured by GC Corporation), to cause setting of the composite resin. Further, the dentin was kept in water at 37 C. for 24 hours to obtain a test sample.

[0141] Shear tests were carried out on 5 test samples using a compact table-top testing machine, EZ-S (manufactured by Shimadzu Corporation), at a crosshead speed of 1 mm/min, an average value of the adhesive strength of the adhesive with respect to enamel (or dentin) was obtained, and the adhesiveness of the adhesive was evaluated based thereon. The categories of the rating scale used to evaluate the adhesiveness are as follows. [0142] A: average value of the adhesive strength is greater than or equal to 25 MPa [0143] B: average value of the adhesive strength is less than 25 MPa

[0144] The evaluations of the tooth substance decalcification inhibiting effect and the adhesiveness of the adhesives obtained in the examples and comparative examples are indicated in Table 1A, Table 1B, and Table 2.

TABLE-US-00001 TABLE 1A EXAMPLE 1 2 3 4 5 6 7 GLASS POWDER Zn 50.5 50.5 50.5 50.5 50.5 50.5 50.5 F 3.0 3.0 3.0 3.0 3.0 3.0 3.0 Al 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Si 33.0 33.0 33.0 33.0 33.0 33.0 33.0 Ca 13.2 13.2 13.2 13.2 13.2 13.2 13.2 P Sr La Na K TOTAL 100 100 100 100 100 100 100 NUMBER 0.5 0.5 0.5 0.5 0.5 0.5 0.5 AVERAGE PARTICLE DIAMETER [ m] ADHESIVE GLASS POWDER 10 20 40 20 20 20 20 20 HEMA 19 18 13.5 18 18 18 19 19 NPG 19 18 13.5 18 19 19 3G 18 18 Bis-GMA 38 35 27 35 25 37.5 37.5 UDMA 35 MDP 10 CQ 2 1.8 1.5 1.8 1.8 1.8 TPO 1.5 1.2 1.1 1.2 1.2 1.2 EPA 4 3.5 3 3.5 3.5 3.5 BPO 2 PA 2 BHT 0.5 0.5 0.4 0.5 0.5 0.5 0.5 0.5 INORGANIC 6 2 2 2 2 2 2 FILLER TOTAL 100 100 100 100 100 100 100 100 TOOTH SUBSTANCE DECALCIFICATION INHIBITING EFFECT MINERAL LOSS 2498 2388 2267 2511 2468 2403 2368 [VOLUME %- m] EVALUATION A A A A A A A ADHESIVENESS ENAMEL A A A A A A A DENTIN A A A A A A A

TABLE-US-00002 TABLE 1B EXAMPLE 8 9 10 11 12 13 14 GLASS POWDER Zn 30.0 26.4 23.8 45.0 49.5 41.7 25.2 F 5.2 6.5 6.8 3.3 3.2 4.7 5.8 Al 0.3 0.3 0.5 0.3 0.1 0.3 0.2 Si 22.9 24.7 23.1 35.5 34.8 37.7 26.8 Ca 7.1 9.6 9.3 11.4 12.1 6.6 P 4.5 Sr 12.4 La 34.5 32.5 36.5 33.2 Na 3.5 K 2.2 TOTAL 100 100 100 100 100 100 100 NUMBER AVERAGE 0.7 0.7 0.7 0.6 0.6 0.4 0.5 PARTICLE DIAMETER [ m] ADHESIVE GLASS POWDER 20 20 20 20 20 20 20 HEMA 18 18 18 18 18 18 18 NPG 18 18 18 18 18 18 18 3G Bis-GMA 35 35 35 35 35 35 35 UDMA MDP CQ 1.8 1.8 1.8 1.8 1.8 1.8 1.8 TPO 1.2 1.2 1.2 1.2 1.2 1.2 1.2 EPA 3.5 3.5 3.5 3.5 3.5 3.5 3.5 BPO PA BHT 0.5 0.5 0.5 0.5 0.5 0.5 0.5 INORGANIC FILLER 2 2 2 2 2 2 2 TOTAL 100 100 100 100 100 100 100 TOOTH SUBSTANCE DECALCIFICATION INHIBITING EFFECT MINERAL LOSS 3042 2979 3211 2742 2955 2719 2974 [VOLUME %- m] EVALUATION A A B A A A A ADHESIVENESS ENAMEL A A A A A A A DENTIN A A A A A A A

TABLE-US-00003 TABLE 2 COMPARATIVE EXAMPLE 1 2 3 4 5 6 7 GLASS POWDER Zn 4.6 F 13.5 13.1 12.0 11.2 9.4 13.2 Al 25.9 23.9 25.9 21.3 21.4 25.5 Si 23.8 24.0 25.1 23.6 20.9 23.3 Ca 0.3 0.1 1.8 P 1.3 4.6 3.5 3.5 1.0 4.4 Sr 35.5 34.1 31.9 28.0 47.3 21.5 La 6.0 4.6 Na 1.5 3.2 K 4.3 TOTAL 100 100 100 100 100 100 NUMBER AVERAGE 0.7 0.6 0.6 0.6 0.7 0.4 PARTICLE DIAMETER [ m] ADHESIVE GLASS POWDER 20 20 20 20 20 20 HEMA 21 18 18 18 18 18 18 NPG 21 18 18 18 18 18 18 3G Bis-GMA 40 35 35 35 35 35 35 UDMA CQ 2 1.8 1.8 1.8 1.8 1.8 1.8 TPO 1.5 1.2 1.2 1.2 1.2 1.2 1.2 EPA 4 3.5 3.5 3.5 3.5 3.5 3.5 BPO PA BHT 0.5 0.5 0.5 0.5 0.5 0.5 0.5 INORGANIC FILLER 10 2 2 2 2 2 2 TOTAL 100 100 100 100 100 100 100 TOOTH SUBSTANCE DECALCIFICATION INHIBITING EFFECT MINERAL LOSS 4542 3615 3890 3865 4050 3892 3769 [VOLUME %- m] EVALUATION C C C C C C C ADHESIVENESS ENAMEL A A A A A A A DENTIN A A A A A A A

[0145] As can be appreciated from Table 1A, Table 1B and Table 2, the adhesives of Examples 1 to 14 have high tooth substance decalcification inhibiting effects and high adhesiveness.

[0146] In contrast, because the adhesive of Comparative Example 1 does not contain glass powder, the tooth substance decalcification inhibiting effect is comparatively low.

[0147] Also, in the adhesives of Comparative Examples 2 to 7, the content of aluminum in the glass powder used was in the range from 21.3 to 25.9 mass % in terms of the amount of aluminum oxide (Al.sub.2O.sub.3) in the glass powder, and as a result, the tooth substance decalcification inhibiting effects of these adhesives are comparatively low.

[0148] The present application is based on and claims priority to Japanese Patent Application No. 2016-117348 filed on Jun. 13, 2016, the entire contents of which are herein incorporated by reference.