evaluation of wear resistance, microhardness and superficial roughness of different fissure sealants after aging.

The aim of this study was to compare the aging effects on wear, surface roughness and microhardness of fissure sealants having varying contents. Four fissure sealant types were used in the study: Aegis (Bosworth, USA) (Group A), Beautisealant (Shofu, Japan) (Group B), Clinpro (3M, USA) (Group C), and Ultraseal XT/Hydro (Ultradent, USA) (Group U). Hundred disc-shaped specimens (5 mm diameter/3 mm width) were designed according to the manufacturer's instructions and assigned for microhardness/Vickers Hardness (VHN), surface roughness, and wear tests. Thermocycling (10,000 times/5-55 °C ± 2 °C/20 s) and chewing simulator (75,000 times/49 N) were applied as the aging procedures. Measurements were made before and after the aging procedures. The specimens were examined by Scanning Electrone Microscopy (SEM). Data was statistically analyzed through Kruskal Wallis, Wilcoxon and Welch tests. The highest and the lowest changes in mean microhardness values were obtained for Group U (9.88 ± 1.46) and Group A (4.40 ± 0.46), respectively; and a significant difference ( < 0.001) was found between the mean changes in microhardness numbers (U > B > C > A). The median roughness values had no significant difference; the surface roughness had the highest mean differences in Groups U and C (U = C > A > B). Significant difference was found between the mean changes in wear/weight values ( < 0.001); the highest and the lowest mean weight losses were recorded in Group U (0.0097 ± 0.0003 gr), and Group C (0.0041 ± 0.0006 gr), respectively (U > B > A > C). The highest physical changes were determined in Group U after the aging procedures. It is concluded that the aging procedures affect physical structures of all test materials with varying degrees, however Ultraseal XT/Hydro is the most affected. The individual treatment needs and material properties must be considered to select a fissure sealant material.