ファイバーで補強したコンポジットレジン試験片に対してコンポジットレジンが破損するまで曲げ加重を付与し，その破壊様式を観察，分類した．

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To improve the esthetics of glass fiber-reinforced resin composite(GFRC) clasps, feasibility of the GFRC clasps with resin coating was evaluated. As a results of thermal cycling and cyclic fatigue tests, the use until three month was found to be possible.

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The aim of this study was to evaluate the mechanical properties of a new commercial hard resin with nano filler and to compare the results with those for the other commercial hard resins. It was suggested that this resin has better mechanical properties compared with the other resins.

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Bond strengths of self-adhesive resin cements (Unicem, 3M ESPE; Maxcem, Kerr; Biscem, Bisco; and Multilink Sprint, Ivoclar Vivadent) were assessed by means of a mocro-shear bond test that measured bonding to small areas of the tooth substrate. Self-adhesive resin cements tested in this study showed low bond strengths to bovine dentin, especially in self-cure modes. Within the limitations of this study, it does not seem that bond strengths of self-adhesive resin cements are high enough. If possible, light cure application may be needed when using the cements.

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The study evaluated the surface roughness, Knoop hardness and weight loss of restorative composites after the samples were immersed in HCl, distilled water and pH-cycling solutions. Two mini filled hybrid restorative composites - Esthet X and Clearfil AP-X were used in this study. Eighteen standardized cylindrical specimens of each material were prepared. After polishing and storing in distilled water for 24 h, the initial weight, Knoop hardness and surface roughness were measured. Then the samples were immersed in the three solutions separately. After the storage of 3 days, 1 week and 2 weeks, the microhardness and the surface roughness of the samples were measured. The weights of the samples were measured after 2 weeks. After 2 weeks, Knoop hardness values of all of the two composites used in this experiment was changed significantly. And the weight loss of the two composites also had a significant difference.

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The output light-intensity distributions from different types of light-curing units, and its effect on polymerization of light-activated conposite resin were investigated. Our results showed that drastic variations in the radiated light intensity across the face of the guide tips for all light-curing units tested. The markedly inhomogeneous light significantly affects the polymerization of the material.

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近年、多くの歯科用コンポジットレジンには診断の際に修復部を判別し易いようにＸ線造影性が付与されている。しかし、どの造影材が最も効果的であるのかは明らかでない。よって本研究の目的は、現在歯科用材料にて使用されている代表的な造影材の化合物を用いた試作コンポジットレジにて半価層を測定することにより、造影材のＸ線不透過性の効果を明らかにすることである。

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Dynamic shear modulus (G'), mechanical loss tangent (tan δ) and degree of conversion of five resin-based restorative materials were measured and the measurement for G' and tan δ were repeated twice. The aim of this study was to elucidate the changes dynamic viscoelastic properties produced due to the repeated measurements.

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Indentation fracture method was applied to calculate contraction stress of resin composite placed in ceramic cavity. The stress was calculated with K_c of the ceramic, dimension of the radial crack and length of crack propagation induced by the contraction.

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The effect of tribochemical silica coating on the bonding between prosthetic resin composites were evaluated and compared with those of alumina particle abrasion. The bond strengths obtained by use of silica coating were significantly influenced by silane-coupling procedures.

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本研究は，ＦＲＣの補強効果を明らかにする目的で繰り返し衝撃荷 重と浸漬温度が曲げ強さに与える影響について検討した．

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コンポジットレジン修復における硬化直後の辺縁部の間隙において，テフロンモールドの辺縁部に生じる間隙の影響を検討した．その結果，コンポジットレジン修復における硬化直後の辺縁部の間隙は，テフロンモールドの辺縁部に生じる間隙に有意に影響されることがわかった．

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We investigated the influence of heat-curing on the bending strength of eight kinds of composite resins. Specimens were prepared with light curing only or with light curing and heat curing. Three-point bending tests were performed and the data were analyzed using two-way analysis of variance (ANOVA). The resins with light and heat curing significantly increased (p<0.05) the bending strength.

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To determine fluorine uptake into enamel around two fluoride-containing materials during pH-cycling, fluorine distribution of the lesion was evaluated using proton induced gamma-ray emission or PIGE technique. Between fluoride-containing materials, there existed some differences in the fluorine uptake with increasing the duration of pH cycling.

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Effects of 4-META treatment of stainless steel fillers on chemical and physical properties of experimental magnetic resin composite material were examined. These properties were also compared with those of commercially available composite resins. The chemical and physical properties of the experimental composite containing 4-META treated fillers satisfied the requirements of ISO 4049:2000 for "Polymer-based filling, restorative and luting materials".

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Structure of the worn surfaces of composite resins after the combined wear test was investigated using an electron probe micro analyzer. The distribution of carbon and silicon, which indicate resin and filler component, on the worn surface was different among the wear test condition, and among composite resins.

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Introduction: Color and translucency of core materials would influence the esthetic performance of final restorations when translucent materials are used as restorative materials. The purpose of this study was to determine the color and translucency of resin-based core materials with a color measuring spectrophotometer. Materials and Methods: Three resin-based core materials, a total of seven shades, were investigated. Specimens, 2 mm in thickness, were made and cured following the manufacturers? instructions. Color of specimens before and after curing was measured with a reflection spectrophotometer over a white background. Color after curing was also measured over a black background. Translucency parameter (TP) was obtained by calculating the color difference between the specimen over the white background and the specimen over the black background: TP = [(L _B * - L _W *) ² + (a _B * - a _W *) ² + (b _B * - b _W *) ² ] ^1/2 . Color changes during curing, and color coordinates and TP values after curing were analyzed with one-way ANOVA by the brand/shade combination of materials (a=0.05). Results: Color change during curing was in the range of 2.4 to 12.0 ∆E*ab units. CIE L* value after curing was in the range of 33.4 to 92.1, and that for chroma was in the range of 4.9 to 17.6. TP value after curing was in the range of 0.4 to 8.1. All the variables were influenced by the brand/shade combination of materials. Discussion: Color and translucency of core materials were significantly different by the shade designation within the same brand. Color change during curing was in the perceptible range (∆E*ab >3.7) in five among seven materials. Core materials are generally opaque compared to restorative materials. Conclusions: Difference in color and translucency of core materials should be considered when selecting a material. Combined color of core and translucent restorative material should be performed to provide clinical selection guide.

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The purpose of this study was to investigate the polymerization activity of the three kinds of different resin composites by using RAP technology and to compare it with those of the conventional initiator system, namely camphorquinone/amine(CQ/amine).

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ファイバーポストと支台築造用レジンとの接着には多くの議論が続けられている．それはファイバーポストの主なマトリックスレジンに熱硬化性樹脂が用いられているためである．しかしながら，ファイバーポストのマトリックスレジンと支台築造用レジンとの接着強さについては明らかとなっていない．本研究では3種類のマトリックスレジンからなるファイバーポストと支台築造用レジンとの接着強さを引抜せん断試験で試験を行い，マトリックスレジンが接着に及ぼす影響を評価した．結果，熱可塑性樹脂で作製したファイバーポストは熱硬化性樹脂で作製したファイバーポストに比べて支台築造用レジンとの接着性は良好であった．

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The purpose of this study was to measure and compare the volumetric polymerization shrinkage of 17 commercially available resin composites. Polymerization shrinkage was measured using volumetric measuring machine - Acuvol™ (Bisco USA).

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本実験の目的は，連続加熱法で成形した PMMA ファイバーポストの曲げ特性に及ぼすガラス繊維体積含有率の影響を明らかにすることである．3点曲げ試験を行った結果，ガラス体積含有率が大となると曲げ弾性係数，曲げ強さも大となり，曲げ弾性係数とガラス繊維体積含有率の関係には複合則が成り立っていることが分かった．これより，ガラス繊維体積含有率を任意に設定することで PMMA ファイバーポストの曲げ特性を設定できることが明らかとなった．

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The purposes of this study were to establish the low temperature silica coating from perhydropolysilazane (PHPS) to resin composite surface under the hydrogen peroxide (H2O2) vapor atmosphere, and to evaluate the effectiveness for the prevention of staining to resin composite. It was concluded that the exposing method to the H2O2 vapor was effective for the formation of silica film on the resin composite and for prevention of discoloration.

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