Effect of cetylpyridinium chloride on dental unit waterline biofilms in-vitro

Abstract

Various disinfectants are used to remove biofilms formed in dental unit waterlines (DUWLs). This study aimed to assess the antibiofilm effects of cetylpyridinium chloride (CPC) on DUWL biofilms formed in a CDC Biofilm Reactor model and evaluate the feasibility of CPC as a novel DUWL disinfectant. For experiments, CPC was used at concentrations of 0.003125% to 0.00039%. Well-established DUWL disinfectants, such as 0.5% sodium hypochlorite (NaOCl), 0.12% chlorhexidine (CHX), and a mixture of 0.12% CHX and 12% ethanol, were used as standards. DUWL biofilms formed in the CDC Biofilm Reactor model were exposed to the disinfecting agents for 15 min. The number of living bacteria in the biofilms before and after exposure to chemicals were compared, and the biofilm reduction rate was calculated. The biofilm reduction rate of CPC at a concentration higher than 0.001562% was greater than that of all other conventional disinfecting agents. These findings suggest that CPC can be used for effective removal of DUWL biofilms.