A pilot study comparing the disinfecting effects of commercialized stable ClO2 solution (free of activation) with conventional H2O2 on dental unit waterlines in the dental practice setting.

Disinfection of dental unit waterlines (DUWLs) plays a key role in control and prevention of nosocomial infection in a dental clinic. The most conventional disinfectant is hydrogen peroxide (H₂O₂), while chlorine dioxide (ClO₂) has been considered however was limited by the "activation" procedures. With the availability of commercialized stable ClO₂ solution (free of activation), direct application of ClO₂ in the dental practice became possible. This study was designed to compare the disinfecting effects of stable 5 ppm of ClO₂ solution with conventional 0.24% of H₂O₂ on DUWLs in dental practice. Studies of colony-forming units (CFUs), confocal laser scanning microscopy (CLSM) and scanning electron microscope (SEM) were employed for evaluation. In CFUs studies, we found that the efficiency of ClO₂ was no less than those of H₂O_2. In the morphological studies, the stronger disinfecting effects of ClO₂ was verified by both CLSM and SEM studies for removal and prevention of biofilm. Importantly, ClO₂ solution achieved a better disinfecting efficiency not only at the surface of bacterial biofilm, but also, it has penetrating effects, presented disinfecting effects from the surface to the bottom of the biofilm. This pilot study provided evidence regarding the efficiency of stable ClO₂ solution on disinfection of DUWLs in the dental practice setting. Application of stable ClO₂ solution in dental practice is therefore become possible.