Comparison of the efficacy of two disinfectants for controlling gram-positive bacteria on thermoplastic retainers in dental plaques

Objective: Thermoplastic retainers are believed to be able to change the ecosystem for the oral cavity microflora. To prevent oral tissue damage, it is vital that retainers are subjected to appropriate cleaning techniques. This study compared the effectiveness of two disinfectants in cleaning thermoplastic retainers against Gram-positive bacteria in the dental plaque layer. Methods: The two disinfectants used in this study were Polident and 0.1% chlorhexidine gluconate. We performed laboratory studies on Gramnegative bacteria using a single-blind setup, with three groups of subjects, each with 13 participants. Results: The results showed that there was a significant reduction in the number of Gram-positive bacterial colonies in the dental plaque layer on retainers cleaned with Polident compared with the control, whereas cleaning the retainer with 0.1% chlorhexidine gluconate showed no significant difference in the number of Gram-positive bacteria compared with the control. Conclusion: We conclude that there is a significant difference in the number of Gram-positive bacteria on the teeth before and after insertion of a thermoplastic retainer in Polident solution, whereas immersion in Minosep did not reduce bacterial numbers compared with that in the control.