The Effect of Different Polishing Techniques on Surface Roughness and Colour Change of Composites

Aim: This study aimed to compare and evaluate the effect of different polishing methods on the surface roughness and colour change of composite resins. Materials and methods: This study used a total of 100 disc-shaped samples made of microhybrid (M) and nanohybrid (N) composite resins. The experimental groups comprised of 5 groups (n=10) for each composite type. The groups were as follows: control (K), diamond bur+polishing rubber (BP), arkansas bur+polishing rubber (AP), diamond bur+polishing rubber+polishing paste (BPP), and disc+polishing paste (DP). Surface roughness (Ra) and initial colour were measured after the polishing methods were tested on all groups. After 7 days of coffee solution application, the colour changes (ΔE) were measured again and the results were recorded. CIEDE2000 formula was used to calculate the colour change. Results: Mann-Whitney U test, Kruskal-Wallis test, and one-way analysis of variance were used in statistical analyses where appropriate. The samples to which disc and polishing paste were applied showed statistically significantly brighter surfaces than the other groups (p<0.05). The highest colour change was observed in the control group and the groups where arkansas stone was applied (p<0.05). Colour change was also higher in the groups with higher surface roughness. Conclusion: Polishing with polishing paste can give good results in polishing and colour stability of composites.