Abrasive wear of enamel by bioactive glass-based toothpastes.

PURPOSE To determine the abrasivity of a 45S5 bioactive glass based toothpaste on enamel as a function of the particle size and shape of the glass. METHODS 45S5 glass was synthesized ground and sieved to give various particle sized fractions < 38, 38-63 and 63-110 microns. Two different grinding routes were used: percussion milling and ball milling. The glass powders were formulated into toothpastes and their tooth brush abrasivity measured according to BS EN ISO11609 methodology. RESULTS Enamel loss increased with increasing particle size. The percussion milled powder exhibited particles that had sharp edges and the pastes were significantly more abrasive than the pastes made with round ball milled powders. One interesting observation made during the present study was that there was preferential wear of the enamel at the dentin-enamel junction (DEJ), particularly with the coarse particle sized pastes.