Antibiofilm activity of irrigating solutions associated with cetrimide. Confocal laser scanning microscopy.

ABSTRACT

AIM: To evaluate the antibiofilm activity of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) solutions associated with cetrimide (CTR), and QMiX using confocal laser scanning microscopy. METHODOLOGY: Enterococcus faecalis (ATCC- 29212) biofilms were induced on bovine dentine blocks for 14 days. The dentine blocks containing biofilm were immersed for 1 min in the following solutions 2.5% NaOCl; 2.5% NaOCl + 0.2% CTR; 2% CHX; 2% CHX + 0.2% CTR; 0.2% CTR; QMiX. After contact with the solutions, the dentine blocks were stained with Live/Dead(®) BacLight for analysis of the remaining biofilm using confocal laser scanning microscope. Images were evaluated using the BioImage_L software to determine the total biovolume (µm(3) ), the green biovolume (live cells) (µm(3) ) and the percentage of substrate coverage (%). The data were subjected to nonparametric statistical test using Kruskal-Wallis and Dunn's tests at 5% significance level. RESULTS: After exposure to irrigants, the total biovolume observed for CHX, CHX+CTR, CTR, QMiX was similar to distilled water (P > 0.05). NaOCl and NaOCl+CTR had the lowest total and green biovolume. The CTR and QMiX had intermediate green biovolume, with greater antibacterial activity than CHX and CHX+CTR (P < 0.05). The NaOCl and NaOCl+CTR solutions were associated with microorganism removal and substrate cleaning ability. CONCLUSIONS: NaOCl and NaOCl+CTR solutions were effective on microorganism viability and were able to eliminate biofilm. The addition of cetrimide did not influence antibacterial activity.