Antibiofilm activity, pH and solubility of endodontic sealers

Abstract

To evaluate antibiofilm activity against Enterococcus faecalis, pH and solubility of AH Plus, Sealer 26, Epiphany SE, Sealapex, Activ GP, MTA Fillapex (MTA-F) and an experimental MTA-based Sealer (MTA-S). Sealer samples were manipulated and stored for 2 or 7days. Prepared sealers were evaluated by a modified direct contact test (DCT) for 5h, 10h or 15h with biofilm previously induced on bovine dentine for 14days. In the control group, the biofilm was not exposed to the sealers. The number of colony-forming units (CFU mL(-1) ) in the remaining biofilm was determined. Sealer solubility was assessed by the percentage of mass loss after 15h of immersion in distilled water. Sealer pH was measured at 5h, 10h and 15h. Statistical analysis was performed using Kruskal-Wallis and Dunn or anova and Tamhane's T2 tests, at 5% significance. At 2days post-manipulation, the DCT showed that Sealapex and MTA-F were associated with a reduction in the number of bacteria in all 3 contact periods evaluated, compared with the control group (P<0.05). At 7days, Sealapex had the greatest antibiofilm action at 10h and 15h. Sealapex had the highest pH values 2 and 7days post-manipulation. Regarding the solubility, at 2days the highest values were observed for MTA-F, MTA-S, Sealapex and Activ GP (P<0.05). At 7days, MTA-S and MTA-F had greater solubility than the other materials (P<0.05). AH Plus had the lowest solubility for both post-manipulation periods (P<0.05). Sealapex and MTA-F were associated with a reduction in the number of bacteria in biofilms and had greater solubility. The high solubility and pH may be related to the antibacterial activity of these materials.