Masashi Komatsu

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This study examined the mechanical properties of a series of Ti-Hf alloys. Titanium alloys with 10 to 40 mass % Hf were made with titanium and hafnium sponge in an argon-arc melting furnace. Specimens cast into magnesia-based investment molds were tested for yield strength, tensile strength, percentage elongation, and modulus of elasticity. Vickers(More)
Nanofiller-containing resin composites have gained appreciable market share in dentistry due to their claims of high mechanical strength and low polymerization contraction. In this study, the polishability of one nanofill (Filtek Supreme XT/FIL) and three nanohybrid materials (Grandio/GRA, Tetric EvoCeram/TET, Venus Diamond/VED) was investigated using(More)
PURPOSE To investigate whether application of three all-in-one self-etching adhesives in a phase-separated stage has an adverse effect on bonding to enamel and dentin. MATERIALS AND METHODS The shear bond strengths (SBSs) on ground enamel and dentin of the adhesives G-Bond, Hybrid Bond, and iBond, combined with Venus composite, were determined. The(More)
PURPOSE For the purpose of evaluating the flow properties influencing the formativeness of commercial hard resin pastes used in the construction of crowns and bridges, we examined the behaviors of various resin pastes and their temperature dependence during manipulation. METHODS Five types of hard resins currently in use for the construction of crowns and(More)
Multiple idiopathic external root resorption of permanent teeth is a very infrequent phenomenon. This paper describes a case of multiple idiopathic external root resorption at cement-enamel junction in 21 of 25 teeth followed up for 6 years. In addition to clinical features and radiographs, we present results of histological and bacteriological examinations.
PURPOSE To evaluate the bond strengths on enamel and dentin with a self-etch adhesive (iBond), with or without oxygen-inhibited surface layer, or covered with intermediate self-curing resin, in combination with chemical-cured composite (Core Paste). METHODS Bond strengths on human enamel and dentin (n = 8) were determined according to the following(More)
The aim of this study was to investigate the wear of four nanofilled resin composites using simulated toothbrushing for 50,000 cycles with calcium carbonate slurry. The depth of abrasion and roughness (Ra) were measured after each 10,000 brushing cycle. The surface texture of the worn samples was examined by SEM.The wear depths of the nanofill Filtek(More)
PURPOSE To determine effects of light curing of self-etching adhesives under ambient air or nitrogen on inhibition depths, enamel and dentin bond strengths, and marginal adaptation in dentin cavities. MATERIALS AND METHODS The adhesives investigated were: AQ Bond (AQB, Sun Medical; Kyoto, Japan), iBond (IBO, Heraeus Kulzer; Hanau, Germany), One-Up Bond F(More)
OBJECTIVES To assess and to compare the effects of Gluma® Desensitizer (GDL) with an experimental glutaraldehyde and HEMA containing fumed silica dispersion (GDG) on dentin permeability using a chemiluminous tracer penetration test. MATERIAL AND METHODS Twenty disc-shaped dentin specimens were dissected from extracted human third molars. The dentin(More)