Antibiofilm activities of denture cleaning tablets against Streptococcus anginosus - Cytotoxic effects on human gingival fibroblast cells
Zeynep Özgen Bölükbaşı, Cemre Özkanca, Ayşe Seher Birteksöz TanBackground and Aims: Streptococcus anginosus and Candida albicans exert negative effects on oral health and can cause biofilm formation on tooth surfaces. Partial or total denture surfaces used by people who have lost their teeth due to various reasons are sensitive to microorganism invasion and biofilm formation, similar to tooth surfaces. Therefore, this study was conducted to investigate the antibiofilm activities of various denture cleaning tablets (DCTs) used to disinfect dentures against S. anginosus clinical isolates and C. albicans standard strain and their cytotoxic effects against oral epithelial cells.
Methods: The biofilm-forming abilities of strains were determined using the crystal violet assay. The modified time-killing curve (TKC) method was used to evaluate the dynamic bactericidal or fungicidal activities of DCTs against biofilms of S. anginosus isolates and C. albicans ATCC 10231. In vitro cytotoxicity experiments of DCTs on human gingival fibroblast cell lines (HGF-1) were also conducted using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide staining method.
Results: Overall, 18.18% and 36.36% of S. anginosus isolates were strong and moderate biofilm formers, respectively. C. albicans ATCC 10231 also formed a strong biofilm. The TKC analysis revealed that all the examined DCTs inhibited almost all living cells in mature biofilms at every time point. The cytotoxic activities of DCTs against HGF-1 cell lines were in the range of 93%–95% at their direct usage concentrations.
Conclusion: DCTs exhibit rapid and strong activity against biofilms, which is extremely important for biofilm-related infections. Nevertheless, it is necessary to consider the cytotoxic effects of DCTs on HGF-1 cells for consumers’ oral healt.