Fumio Nishimura

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Bisphenol A (BPA) is an endocrine disruptor, and is used as a raw material for bisphenol A diglycidyl methacrylate and polycarbonate, that are used in the dental materials. In this study, the total and released amounts of BPA from polycarbonate-based dental materials were measured with high-pressure liquid chromatography (HPLC). The specimens used were(More)
Knowledge of thermal conductance of carbon nanotubes under mechanical deformation is important to characterize the robustness of carbon nanotube heat conduction. In this study, using molecular dynamic simulations, we have calculated thermal conductance of an elastically buckled single-walled carbon nanotube. A local buckle was formed by mechanically bending(More)
The purpose of this study was to investigate the effects of the location and orientation of dentinal tubules in the tooth on tensile strengths of the dentin. Dumbbell-shaped specimens of 12 groups from various locations and dentinal tubule orientations were prepared. The tensile test was performed in distilled water at a temperature of 37 degrees C. The(More)
The purpose of this study was to compare the fatigue and tensile strengths of radicular dentin. Forty bovine lower central incisors were used, twenty teeth for the fatigue test and twenty teeth for the tensile test. Bovine teeth were each sectioned into coronal and radicular portions. Dentin slabs of 1mm thickness were prepared along the radicular tooth(More)
Bisphenol A (BPA) is an endocrine disrupter, and is used as a raw material for bisphenol A dlglycidyl methacrylate and polycarbonate, that are used in the dental materials. In this study, the total and reteased amounts of BPA from polyearbonate-based denta] materials were measured with high-pressure liquid chromatography (HPLC). The speeimens used were(More)
OBJECTIVE The purpose of the present study was to investigate the tensile strengths of dentin after laser irradiation using three kinds of dental lasers to elucidate the laser-irradiation effect on dentin properties. BACKGROUND DATA Different kinds of laser devices have been developed in dentistry. The characteristics of each laser are determined by its(More)
In one aspect, this study examined the tensile strength of coronal dentin, as a function of the location of incremental lines, in two types of teeth: human molar versus bovine incisor. In another aspect, tensile strength in coronal dentin was examined with tensile loading in two different orientations to the incremental lines: parallel versus perpendicular.(More)
This study investigated the hardness and Young's modulus of coronal and radicular intertubular dentin. Ten bovine teeth were each divided into coronal and radicular groups, and the flat surfaces of the coronal and radicular dentin were subsequently processed along the tooth axis. The hardness and Young's modulus of the coronal and radicular intertubular(More)