in vitro effects of four porcelain surface treatment methods on adhesion of lactobacilli acidophilus

objective: adhesion of lactobacillus acidophilus (l. acidophilus) to dental porcelain surface may lead to gingival inflammation and secondary caries. surface roughness is among the factors affecting this adhesion. the purpose of this study was to evaluate the effects of four different surface treatment methods on adhesion of l. acidophilus to dental porcelain.   methods: sixty specimens (3x10mm) were fabricated of noritake porcelain and divided into 4 groups (n=15) treated with one of the following four surface finishing techniques: 1. auto-glazing 2. over-glazing 3. polishing with kenda kit and 4. no surface treatment (non-glazed specimens). specimens were inoculated with bacterial suspension containing 1x106colony forming units per milliliter (cfu/ml) and l. acidophilus adhesion to the surfaces was evaluated using a spectrophotometer. data were analyzed using one-way anova and tukey’s hsd test.   results: the mean bacterial adhesion was 0.1440 (0.00429) to auto-glazed specimens, 0.0750 (0.00256) to over-glazed specimens, 0.1800 (0.00325) to polished specimens and 0.7064 (0.00408) to the non-glazed specimens. the differences in this regard among groups were statistically significant (p<0.001).   conclusion: over-glazed specimens caused the lowest and non-glazed specimens caused the highest bacterial adhesion. the glazed surfaces caused less adhesion than the polished surfaces.