The Effect of Different Polishing Methods on the Surface Roughness of Resin Composites (An In-Vitro Study)

Abstract

Since polishing of resin composites is a crucial step for the longevity and final esthetic outcome of restorations. This study was conducted to evaluate the effect of one-step, two-step and multi-step polishing systems on the surface roughness average (Ra) of nanofilled and suprananofilled resin composite materials. A total of 56 resin composite discs were prepared (divided into 2 main groups of 28 discs each according to the tested composite material, where Group FK (Filtek™ Z350 XT Universal Restorative - 3M ESPE Dental Products), and Group OM (Omnichroma - Tokuyama Dental) using split Teflon mold and cured against Mylar celluloid strip. Except for control group, samples were manually ground with wet 600-grit silicon carbide paper for 30 seconds, and then subdivided into 3 groups (n = 7) in each main group, where Group ES (Enamel Plus Shiny polishing pastes - Micerium), Group SS (Super-Snap X-treme aluminium oxide discs - Shofu INC), and Group OG (OneGloss® - Shofu INC) polishing systems. Each polishing protocol was done according to the instructions of their corresponding manufacturers, in the same direction at a very slow rotational speed of 3000 rpm, using a kitchen scale to maintain each stroke pressure approximately 30-40 gm (approximately 0.3 newton). Scanning electron microscope (SEM) was used to scan all samples, and the images were subjected to Gwyddion 2.56, (An SPM data visualization and analysis tool) supported by