Comparison of roughness and microhardness of conventional and bulk fill composite resins.

Abstract

ABSTRACT

Introduction: With the advancement of Dentistry, the search for restorative materials that combine aesthetics and improved mechanical properties has grown. Conventional and Bulk Fill composite resins are widely used, but they present differences in their composition and clinical performance. This study evaluated the surface roughness and microhardness of three types of composite resin. Objective: To compare the surface roughness and microhardness of Z350 XT and Zirconfill® (conventional) and Filtek™ One Bulk Fill resins. Methodology: Twenty specimens were prepared for each resin, molded in plastic matrices and polymerized with a Valo Cordless light curing unit. Roughness was measured with a Surtronic 25 roughness meter, while Vickers microhardness was evaluated on the upper and lower surfaces. Statistical analysis included ANOVA and Tukey and Games-Howell tests. Results: Z350 XT and Zirconfill® presented lower roughness values, while Bulk Fill had a more irregular surface. Regarding microhardness, Z350 XT demonstrated a higher top-to-bottom ratio, suggesting more efficient curing due to the incremental technique. Statistically significant differences were observed between the tested materials. Conclusions: Z350 XT and Zirconfill® resins showed better performance in surface finishing, while Bulk Fill presented greater roughness and lower microhardness. These findings suggest that conventional resins are more suitable for restorations demanding in terms of esthetics and resistance.

Keywords: composite resin, surface properties and hardness tests.