Abstract
Bacterial adhesion over composite restorations may lead to secondary caries and periodontal inflammation. Post-curing finishing/polishing aim to reduce this exposure. This study investigated and compared the degree of single species Streptococcus mutans (S. mutans) and multi-species salivary biofilm adhesion on four restorative composites across three finishing/polishing systems. Standardized disc samples (2x 10mm) were produced from each composite material. Ten discs of each material were subjected to three finishing and polishing systems. Half the samples (n=5) were incubated in human saliva and the other half were incubated in S. mutans for biofilm development for 48 and 24 h, respectively. Following dilution and bacterial growth, the mean number of colony forming units (CFU/mLx5; log10) was counted using a colony counter and analyzed using SPSS Statistics V22.0. Data were analyzed using three-way analysis of variance and the Tukey's post-hoc tests (p<0.05). There were no significant differences in biofilm adhesion in the saliva incubation group across the three polishing systems (F=1.138; p=0.328) or the four types of materials (F=1.001; p=0.399). There were significant differences in biofilm adhesion in the S. mutans group across the three polishing systems (F=3.918; p=0.025) and the four types of materials (F=3.899; p=0.013). Multiple comparisons revealed that biofilm adhesion was lowest in the Astropol (R) group. Filter (TM) Bulk Fill had significantly lower biofilm adhesion than Filter (TM) Z350 XT (p=0.008). Surface properties vary by composite materials and finishing and polishing techniques, which influences bacterial adhesion. The least bacterial adhesion was observed with Sof-LexTM finishing and polishing system and Filtek (TM) Bulk Fill composite material..