SCANNING LASER MICROSCOPIC SURFACE PROFILES OF HUMAN ENAMEL AND DENTIN AFTER BRUSHING WITH ABRASIVE DENTIFRICE INVITRO

Automatic brushing with and without commercial dentifrice containing c alcium hydrogenphosphate as an abrasive, commonly available in Japan, was performed on the tangential ground surfaces of sound enamel and de ntin in human young premolar teeth with loading of about 120 g for 10 minutes in vitro. Their brushed surfaces were observed with a scanning electron and a scanning laser microscope. Brushing with abrasive dent ifrice caused rough surfaces to appear and the abrasion of the enamel and the dentin was measured to be about 0.1 and 1.5 mum/min in mean de pth, respectively. Under brushing with only distilled water, however, the enamel surfaces remained intact while the dentin surfaces became s moother.