In vitro effect of two prophylaxis methods on adherence of streptococcus mutans to the surface of microfilled composite and giomer

Abstract

Restoration surface topography has a great role in adherence of plaque bacteria. Since prophylaxis methods are one of the factors involved in damaging and even destroying the surface of cervical restorations the aim of the present study was to evaluate the effect of two prophylaxis methods on adherence of Streptococcus mutans to the surface of microfilled composite resin and giomer. Materials and Methods: A total of 60 composite resin and 60 giomer specimens were used in the present study; the specimens were cylmdrical in shape with a diameter of 6 mm and a height of 2 mm. In each group the specimens were randomly subdivided into three groups of 20 specimens each. In the first group (the control) the specimens did not undergo any prophylaxis procedures. In the second and third groups the specimens underwent prophylaxis with pumice and rubber cup and air-powder polishing device (APD), respectively. The surfaces of some selected specimens from each group were evaluated under a scanning electron microscope; the surface topography produced by the two prophylaxis methods was determined by atomic force microscopy. The extent of the adherence of Streptococcus mutans to surface of specimens was determined after 4 hours of immersion in bacterial innoculum, rinsing and sonication by plate counting method. All data were analyzed by two-factor ANOVA and a post hoc Tukey test. Statistical significance was set at P<0.05. Results: The means of bacterial adherence in relation to the restorative material and the method used for prophylaxis were statistically significant (P<0.0005). Bacterial adhesion was significantly higher in composite groups compared to giomer groups. In each material, bacterial adherence was significantly lower in the control group compared to the groups undergoing prophylaxis. Prophylaxis with pumice and rubber cup resulted in significantly less bacterial adherence compared to prophylaxis with APD. Conclusion: Based on the results of the present study, giomer specimens demonstrated less bacterial adherence compared to composite resin specimens.