Wear of commercial pit and fissure sealants.

The objective of this study was to compare the abrasion resistance, resistance to penetration, and mode of deformation of a filled (A*) and two unfilled (Bt and C$) pit and fissure sealants. Samples were mixed following manufacturers' instructions and stored at 37 C for 24 hours before testing. Five cylindrical samples of each sealant were abraded on silicon carbide paper§ with continuous flushing with water by a twobody abrasion test (POWI RS et al. JADA 89: 11 18, 1974). The surfaces of five samples of each sealant c Lred in a sample holder were scratched by a diamond hemisphere (360 um in diameter) at normiial loads of 1 to 10 N in increments of 1 N by a procedure described elsewhere (POWERs and CRAIG, JDent Res 51:168, 1972). The wear track width (W) was mcasured and surface failure evaluated by a scanning electron microscope (SEM) Means of the abrasion data (standard deviations in parentheses) were A. 23.3 (1.4); B. 21.5 (1.1); and C, 23.9 (2.2) X 10-4 mm3/mm of travel. There were no significant differences