To compare the enamel surface roughness produced by three polishing systems before and after bracket debonding.
Method:
Forty five (45) human first premolars were randomly divided into three groups of 15 specimens each, according the polishing system evaluated: Sof-Lex™ (3M ESPE, St. Paul, Minnesota, USA), Enhance™ (DENTSPLY Caulk, Milford, Delaware, USA) and Fiberglass™ (TDV Dental, Pomerode, Santa Catarina, Brasil). Enamel three-dimensional surface roughness was analyzed before cementation using a Confocal Laser Microscope, while enamel condition (ESI index) was analyzed with a Scanning Electron Microscope. Standard brackets were cemented with a light-cured adhesive and after 24 hours debonded using a debonding Plier. Remaining resin on enamel surface was removed using a multi-blade tungsten carbide bur and verified clinically by visual inspection under a dental operating light. Then, enamel was polished using the three systems evaluated. After that, surface roughness and enamel condition were analyzed again using the techniques mentioned previously in order to determinate the differences between baseline and enamel surfaces after polishing. Statistical analysis for baseline enamel roughness was performed using one way ANOVA. After polishing, roughness and enamel condition were evaluated using Kruskal Wallis and Mann Whitney U tests.
Result:
Before polishing, enamel three-dimensional roughness was not statistically different when groups were compared (p>0,05). Roughness after polishing showed a statistical significant difference (p<0,05) between Enhance (3,11µ) and the other two systems (Sof-lex and Fiberglass). No difference was observed between the last two (4,59µ vs. 4,99µ respectively). Before and after polishing comparisons showed a statistical significant roughness decrease in all groups (p<0,05). Enamel condition after polishing was statistically different when groups were compared (p<0.05). Fiberglass produced more imperfect and unacceptable enamel surfaces than the other two systems.
Conclusion:
The three systems evaluated generate a decrease on the enamel surface roughness. However, enamel condition is affected when fiberglass is used.