ABRASIVE PROPERTIES OF COMMONLY USED DENTIFRICES

抄録

This study was conducted to examine the effect of various dentifrices on the abrasion of acrylic resin and extracted human tooth. The influence of the difference in the hardness of the filament of the toothbrush on the abrasion was also studied, using three kinds of toothbrushes. The specimens (acrylic resin and extracted human tooth) were brushed 3.,000 times by the back­ and -forth stroke movement using a toothbrushing machine for two hours. The surface irregularities of the specimen were analyzed by the surface analyzer and observed by the scanning electron microscopy before and after the brushing procedure. Moreover, the weight loss of the test specimens of the acrylic resin materials was determined, weighing them by a microbalance before and after brushing. The abrasiveness of the dentifrices showed a wide range, but the abrasiveness of the toothbrush itself was not observed. All dentifrices except one which did not contain the abrasive materials had abrasive effects on both the acrylic resin and human tooth. There was a high correlation (r=0.96) between the weight loss and the surface irregularities in the case of acrylic resin.