Roughness of a nanohybrid composite with different polishing methods

Method:

18 disc-shaped specimens were prepared using nanohybrid composite Herculite XRV Ultra. Five different polishing methods were then applied (A to E) and the control group F remained without polishing (n=3). The polishing methods tested were: A – Optidisc (Kerr) , B – HiLuster (Kerr) , C – Arkansas stone, D – Enamel Plus Shiny (Micerium) and E – Dimanto (Voco). The polished surface of each specimen was analyzed with a rugosimeter (SE12000 - Kosaka Lab^®, model no: DR-25X11, IST) and two measurements were made per specimen. 

Result:

The data provided evidence that the average roughness differed among the six treatment groups (p< 0.05). The groups with the lowest Ra values were Optidisc (0,30±0,077) and Enamel Shiny (0,37±0,058), without statistical significance among them. These groups clearly differed from the three groups with the highest Ra values: Control (1,014±0,369), Arkansas (0,693±0,218) and HiLuster (0,572±0,184). The Dimanto group (0,568±0,176) obtained a medium value of roughness, however without statistical differences when compared with Enamel Shiny and HiLuster. After pairwise comparisons of the groups the statistical differences found can be grouped as follows: Optidisc® = Enamel Shiny® < Enamel Shiny® = Dimanto® = HiLuster® < Dimanto® = HiLuster ® = Arkansas < HiLuster® = Arkansas = Control.

Conclusion: The Optidisc ® and Enamel Shiny® polishing systems revealed the lowest roughness values.  The highest values were observed on the control group (F). Although it seems essential to always polish restorations, the right choice of the polishing method may be as critical.