Use of two surface analyzers to evaluate the surface roughness of four esthetic restorative materials after polishing

This study had two aims: determine how well four esthetic restorative materials lent themselves to polishing and compare the results obtained using two different techniques for evaluating surface roughness. The four materials used were two composites modified by the addition of resin, Dyract AP (Dentsply) and Dyract Flow (Dentsply); one composite designed for posterior restorations, SureFil (Dentsply) and one universal micromatrix composite, Esthet-X (Dentsply). Five test pieces were made with each product by inserting the material into cylindrical molds and polymerizing it layer by layer. A single operator polished the specimens on the same day using the Enhance system (Dentsply) and two aluminum oxide pastes. The surfaces were studied successively by means of two surface analyzers: a high-resolution optical profilometer (Nanosurf 488, SAS Technology) and a mechanical profilometer (Mitutoyo Surftest-SV 402). These measurements gave the mean roughness of the surface (Ra). Ten zones were examined for each specimen, and the specimens were observed under an optical microscope (PMG3 inverted metallographic microscope) at 50x magnification. The qualitative and quantitative analyses of the results showed good surface states for all materials. However, the composites based on nano- and micro-filler technology gave the smoothest surfaces after polishing. A comparison of the values obtained with each method of observation showed that mechanical profilometry tended to show roughness caused by polishing, while optical profilometry brought out roughness due to the structure of the material itself.