To evaluate the effects of different polishing methods on a nanohybrid composite resin surface by scanning electron microscopy (SEM) analysis.
Method:
18 disc-shaped specimens were prepared using a nano-hybrid composite Herculite XRV Ultra (Kerr). Five different polishing methods were tested (A to E) with the control group (F) remaining 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 specimens were prepared for SEM analysis and micrographs were taken at 50x, 100x and 500x magnification (Hitachi S-450®, University of Lisbon, School of Dentistry, Lisbon, Portugal).
Result:
The different polishing methods yielded different surface patterns. On the Optidisc group a linear pattern was observed on the composite surface, with paralel sulcs; the Hi-luster group presented a uniform surface, without a defined pattern, only with small oblique sulcs with different depths; the Enamel Shiny group showed a mixed pattern with linear and rounded areas of substance loss; the Dimanto group exhibited a dotted surface with round areas of variable diameter. Major irregularities were observed on the control group where no polishing method was applied.
Conclusion:
Different polishing methods create different surface textures and patterns, due to differences in composition and shape. It seems important to polish all composite restorations since an unpolished surface presents the most irregular pattern.