Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices最新文献_第10页

[On mechanical behavior of molecular composite resins reinforced with polyaramides. Molecular motion of Oct-PPTA and Ste-PPTA and thermal properties and dynamic viscoelasticity of Oct-PPTA-PMMA and Ste-PPTA-PMMA]. 聚酰胺增强分子复合树脂力学性能研究。Oct-PPTA和st - ppta的分子运动及Oct-PPTA- pmma和st - ppta - pmma的热性能和动态粘弹性[j]。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

S Higuchi

{"title":"[On mechanical behavior of molecular composite resins reinforced with polyaramides. Molecular motion of Oct-PPTA and Ste-PPTA and thermal properties and dynamic viscoelasticity of Oct-PPTA-PMMA and Ste-PPTA-PMMA].","authors":"S Higuchi","doi":"","DOIUrl":"","url":null,"abstract":"Molecular composites, composed of polymethylmethacrylate (PMMA) resin as matrix reinforced with polyaramides as a rigid core molecule have been developed to produce a denture base polymer with improved dental material properties. N-substituted polyaramides were prepared via metalation using sodium methylsulfinylcarbanion, followed by the reaction with corresponding octyl bromide and/or stearyl bromide in dimethyl sulfoxide. In these molecular composite resins (called Oct-PPTA-PMMA and Ste-PPTA-PMMA short) compounding 3 wt% of N-octylated-PPTA (Oct-PPTA) and/or N-stearylated-PPTA (Ste-PPTA) to PMMA, their dental material properties were in the order of Oct-PPTA-PMMA greater than Ste-PPTA-PMMA greater than or equal to PMMA. Their polymer properties were analyzed to molecular level, using nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric (TG) analysis and dynamic mechanical thermal analysis (DMTA). The molecular motion of the methyl group of Oct-PPTA proved to be constrained for the rigid main chain by T1 (inversion recovery method) NMR spectra in CDCl3 while that of Ste-PPTA was not affected. The thermal properties of the composites were in the order of Oct-PPTA-PMMA greater than Ste-PPTA-PMMA greater than PMMA by TG analysis, and the dynamic storage modulus values were Oct-PPTA-PMMA greater than Ste-PPTA-PMMA greater than PMMA in the region from rubbery state to viscous flow state by DMTA.","PeriodicalId":77622,"journal":{"name":"Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Influence of metal elements in Pd alloys on the bonding to porcelain]. [Pd合金中金属元素对陶瓷结合的影响]。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

Y Kurisaki, K Nagayama

{"title":"[Influence of metal elements in Pd alloys on the bonding to porcelain].","authors":"Y Kurisaki, K Nagayama","doi":"","DOIUrl":"","url":null,"abstract":"The influence of metal elements in three Pd alloys on the bonding to porcelain was examined. The high-temperature oxidation behavior of metal elements in alloys, structure and morphology of oxidation zones on the alloy surface and the appearance of bonding between alloy and fused porcelain at the interface were studied by ESCA and EPMA. From ESCA analysis, metal oxides such as PdO, SnO2, In2O3, CuO or Cu2O, Sb2O3 or Sb2O5 were formed on the surface of the alloy after degassing (preheating) and heating following casting. The amount of metal elements concentrated on the alloy surface was measured by their characteristic X-rays using area analysis of EPMA under the technical conditions of A) Acc. voltage 10 kV, Abs. current 40 nA, and B) Acc. voltage 20 kV, Abs. current 10 nA. Consequently, the amount of additive metal elements concentrated on the alloy surface which was detected in condition A) was larger than that detected in condition B). However, the amount of main element (Pd) concentrated on the alloy surface which was detected in condition A) was smaller than that detected in condition B). From the EPMA observation of the interface between alloy and fused porcelain, cross-section of alloys showed that the additive metal elements were oxidized in the alloy matrix, forming an internal oxide layer or particles. The structure and morphology of oxidation zones showed a significant difference between degassed and not-degassed alloys. Cross-sections inclined approximately 5 degrees 43' to the fusing boundary were also analyzed to enlarge the oxidation zones. This analytical technique effectively revealed the structure and morphology of oxidation zones. In conclusion, not only additive metal elements but also the main element at the surface of alloys play important roles on the bonding to porcelain. Degassing of the alloy was considered to an essential procedure to obtain the adequate bonding to porcelain.","PeriodicalId":77622,"journal":{"name":"Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Application of microwave for dental technique. 5. Injection molding system for resin base denture]. 微波在口腔技术中的应用。5. 树脂基托假牙的注射成型系统。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

H Kimura, F Teraoka, M Sugita

引用次数: 0

[A novel reactive polymer bonding composite resin to ground tooth substrates]. 一种新型反应性聚合物结合复合树脂与磨齿基板。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

T Kinoshita

{"title":"[A novel reactive polymer bonding composite resin to ground tooth substrates].","authors":"T Kinoshita","doi":"","DOIUrl":"","url":null,"abstract":"Methyl methacrylate (MMA)-p-styrene sulfonic acid copolymer (MS) was prepared and its adhesion to ground tooth substrates was evaluated. MS is crosslinked with Ca2+ supplied by hydroxyapatite in the smeared layer on the ground enamel and dentin, and sticks to their surface. The adhesion mechanism of MS is quite different from that of interpenetration and polymerization of monomers. The bonding strength of MMA-TBB resin to the tooth treated with an aqueous solution of MS was 11-12 MPa but that of MMA-BPO.DMPT resin was only 2.5 M Pa. Free sulfonic acids remaining in the immobilized MS disturbed the initiation of polymerization in MMA-BPO.DMPT resin. A photocurable liner, triethylene glycol dimethacrylate (TEGDMA) activated by d,l-comphorquinone (CQ), N-phenylglycine (NPG), which was polymerized in an acidic condition by irradiation, was chosen to obtain a high bond strength to the cross-linked MS on the tooth. The bond strength of TEGDMA-CQ.NPG on the tooth treated with an aqueous mixture of 10 wt% MS 7 (MMA: 70 mol%, p-styrene sulfonic acid: 30 mol%) and FeCl3 ([Fe3+]/[SO3-] = 0.28) was 10-11 MPa. The observation of the fractured surface after the tensile test and interface between precipitated MS and tooth indicated that the liner did not interpenetrate into the dentin through the immobilized MS on the tooth. These results indicated that the polymer reaction of MS with Ca2+ was important in the adhesion. In conclusion, MS is a reactive polyelectrolyte which adheres well to tooth substrates and prevents pulp irritation by hindering the penetration of the monomer.","PeriodicalId":77622,"journal":{"name":"Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Grinding of titanium. 2. Commercial vitrified wheels made of alumina abrasives]. 钛的研磨。2. 氧化铝磨料制成的商用玻璃化车轮。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

O Miyakawa, K Watanabe, S Okawa, S Nakano, N Shiokawa, M Kobayashi, H Tamura

{"title":"[Grinding of titanium. 2. Commercial vitrified wheels made of alumina abrasives].","authors":"O Miyakawa, K Watanabe, S Okawa, S Nakano, N Shiokawa, M Kobayashi, H Tamura","doi":"","DOIUrl":"","url":null,"abstract":"Cast titanium was ground with commercial vitrified wheels made of alumina abrasives, and their grinding performance was investigated. For cutting, the appropriate circumferential speed of the alumina wheels was about 700 m/min. A speed lower or higher than this yielded unfavorable grinding results, which were attributed to wheel loading or chemical attrition of the abrasive, respectively. The hard wheel made of the A abrasive was suitable for grinding of titanium, and moreover, the wheel of the WA abrasive was more suitable than that made of the A abrasive. Generally, the cutting rate of the alumina wheels was inferior to that of the silicon carbide ones investigated previously. Depression of the wheel against the work yielded unfavorable grinding results; the manner in which the wheel was moved over the work during grinding was very important, compared with the silicon carbide wheels. Although the wheel was moved over the work, the high circumferential speed of the wheel resulted in chemical attrition of the abrasive and discoloration of the work surface, or grinding burn. The grinding burn layer mainly consisted of a few microns-thick titanium oxide.","PeriodicalId":77622,"journal":{"name":"Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Transmittance of light-cured composite resins. 1. Measurement of transmittance with time]. 光固化复合树脂的透光率。1. 透光率随时间的测量]。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

K Komatsu, K Nemoto, K Horie

{"title":"[Transmittance of light-cured composite resins. 1. Measurement of transmittance with time].","authors":"K Komatsu, K Nemoto, K Horie","doi":"","DOIUrl":"","url":null,"abstract":"The factors that influence the change of the transmittance of light-cured composite resins during polymerization were examined. Six experimental composite resins such as used organic composite filler and fourteen commercial composite resins were investigated using the experimental device for measurement of the transmittance. The transmittance of the experimental composite resins were from 25 to 73%. The transmittance of the experimental composite resins changed with time; a group with increasing transmittance (G1), a group giving a maximum transmittance (G2), and a group with decreasing transmittance (G3). These changes of transmittance were influenced by the difference in the refractive indices between matrix resin and filler, but the refractive index that indicated a maximum transmittance of matrix resin during polymerization could not be observed when the refractive index of the matrix resin and filler was same. The light transmitted through the commercial composite resins was less than half of the irradiation light. This change of transmittance could also be classified into the three groups mentioned above. The commercial composite resins belonged to the group with increasing transmittance (G1).","PeriodicalId":77622,"journal":{"name":"Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Bond strength of dental luting cements to titanium castings]. [牙套黏合剂与钛铸件的结合强度]。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

Y Hibino, A Kuroiwa, S Kurosawa, S Kanke, H Hashimoto

引用次数: 0

[The surface degradation of various light-cured composite resins by thermal cycling]. [各种光固化复合树脂的热循环表面降解]。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

S Hirabayashi, R Nomoto, I Harashima, T Hirasawa

{"title":"[The surface degradation of various light-cured composite resins by thermal cycling].","authors":"S Hirabayashi, R Nomoto, I Harashima, T Hirasawa","doi":"","DOIUrl":"","url":null,"abstract":"The durability of four commercially available light-cured composite resins was investigated by thermal cycling, GR containing inorganic fillers treated with the graft polymerization of acryl ester, LF inorganic fillers treated with a silane coupling agent, PC silanized inorganic fillers and organic composite fillers, and the MFR-type SI containing the organic composite fillers. These materials were given 10,000, 30,000 and 50,000 thermal cycles (4 degrees C-60 degrees C) and the deterioration of materials by thermal cycling was evaluated by the measurement of the mechanical properties and the SEM observations of the surface of the thermocycled materials. Compressive strength and bending elastic moduli for all materials did not change greatly by thermal cycling. However, bending strength, toothbrush abrasion resistance and surface hardness decreased with increasing number of thermal cycles between 0 and 30,000, and changed little after 30,000 cycles. The percentage of bending strength after 50,000 thermal cycles to that of the non-thermocycled sample was 75% for GR, 60% for LF, 50% for PC and 65% for SI, respectively. Deterioration of materials was observed as cracks on the surface, which generated at the interface of the filler and matrix. The cracks generated relatively earlier during thermal cycling for SI and PC which contained the organic composite filler, later for LF which contained the silanized inorganic fillers, and the number of cracks on LF were fewer than SI and PC. On the other hand, for GR, no cracks were observed even after 50,000 thermal cycles. From these results, it can be presumed that the pre-treatment of filler by the graft polymerization is more effective to improve the durability of composite resin.","PeriodicalId":77622,"journal":{"name":"Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Grinding of titanium. 1. Commercial and experimental wheels made of silicon carbide abrasives]. 钛的研磨。1. 商用和实验用碳化硅磨料制成的砂轮。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

O Miyakawa, K Watanabe, S Okawa, S Nakano, N Shiokawa, M Kobayashi, H Tamura

{"title":"[Grinding of titanium. 1. Commercial and experimental wheels made of silicon carbide abrasives].","authors":"O Miyakawa, K Watanabe, S Okawa, S Nakano, N Shiokawa, M Kobayashi, H Tamura","doi":"","DOIUrl":"","url":null,"abstract":"Cast titanium was ground with commercial and experimental wheels made of silicon carbide abrasives, and their grinding performance was investigated. With the vitrified wheels made of the GC abrasive, at a higher the wheel circumferential speed and heavier the grinding pressure, the cutting rate was greater, accompanied by violent wear of the wheel. Being independent of the wheel speed, the grinding ratio reached about 1 under pressure heavier than 100 gf. The MgO-MgCl2-bonded wheels of the C abrasive exhibited a similar tendency. The manner in which the wheel was moved over the work during grinding proved to be very important, compared with the Ni-Cr alloy as reported previously. Only depression of the wheel against the work resulted in chemical attrition of the abrasive and discoloration of the work surface, or grinding burn, due to oxidation of titanium. Even when the wheel was moved over the work, chip-formation process of the cutting edge was far from ideal, and the work surface was contaminated due to reaction of titanium with the abrasive. At a higher wheel circumferential speed, more chips were loaded or built-up in the wheel and strongly rubbed the work surface, resulting in violent wear of the wheel; loading and dislodging of such chips were repeated.","PeriodicalId":77622,"journal":{"name":"Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13289743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

[Adhesion of restorative resin to tooth substance. Treatment of tooth surface with aqueous solution of amino-acid derivatives and HEMA]. 修复树脂对牙齿物质的附着力。氨基酸衍生物和HEMA水溶液对牙齿表面的处理[j]。

Shika zairyo, kikai = Journal of the Japanese Society for Dental Materials and Devices Pub Date : 1990-01-01

M Takahashi, K Suzuki, H Nakai

引用次数: 0