Surface deterioration of resin composites and enamel after toothbrush simulation with new and used toothbrushes.

Purpose: To investigate the effect of toothbrushing with new and used toothbrushes on the surface of resin composites and dental enamel.

Methods: The extracted human incisors were selected after vestibular enamel surfaces (ES) were examined. Disc-shaped specimens of direct composite (DC) and indirect composite (IC) were fabricated. Computer-aided design-computer-aided manufacturing (CAD-CAM) composite blocks (CC) were sliced in 2 mm thickness (n= 8). The surface roughness, gloss, and color were measured. The measurements were performed before and after 3 months of toothbrushing simulation (TBS) for 2,500 circular cycles. The wear index was calculated by using the ImageJ program. The specimens were subjected to an additional 2,500 cycles and the same measurements were repeated.

Results: No significant increase in surface roughness values was observed in DC, IC, and CC groups after 3 and 6 months of TBS except in the ES group. The highest change in surface gloss was observed in the DC group. Although the wear index of toothbrushes increased over time, only the increase in the IC group was statistically significant (P= 0.033).

Clinical significance: Changes in surface roughness, gloss, and discoloration of the dental enamel and restorations and wear of toothbrush bristles were increased over time.