The Effect of Additional Finishing and Polishing Sequences on Hardness and Roughness of Two Different Dental Composites: An In Vitro Study

Aim: The aim of this study was to evaluate the effect of additional finishing and polishing sequences on a new structural colored (Omnichroma) and a conventional dental composite (Estelite Sigma Quick). Materials and Method: Forty disk-shaped dental composite specimens were prepared from each dental composite and assigned to four groups in terms of additional finishing polishing sequences. Group 1: Mylar strip (control). Group 2: Abrasive disks. Group 3: After abrasive disks, application of a felt brush with abrasive paste. Group 4: After abrasive disks, application of a felt brush with abrasive paste. Then, a single-bottle adhesive was applied as a surface sealer. Hardness and surface roughness were measured using the Vickers hardness test and a profilometer, respectively. SEM images of one of each group were captured at 500x, 1500x, and 3500x magnifications. Two-way analysis of variance, Tukey HSD, and Shapiro-Wilk tests were used for the statistical analysis. Results: Mean hardness values differ in terms of finishing-polishing sequences (P < .001), dental composites (P < .001), and interaction of finishing-polishing sequences-dental composites (P < .001). Mean roughness values differ in terms of finishing-polishing (P = .002). The main effect of composites on roughness values was not found statistically significant (P = .990). Also, there is no difference between the mean roughness values in terms of the interactions of finishing-polishing and composites (P = .967). Conclusion: Finishing-polishing with abrasive disks and abrasive paste are important steps for these dental composites. However, the application of a single-bottle adhesive as a surface sealant on these composites decreases the hardness of the materials.