Disinfection effects of intelligent water treatment system on dental unit waterlines

Abstract

Objective To investigate the disinfection effect and cytotoxicity of intelligent water treatment system on dental unit waterlines (DUWLs) , so as to provide basis for the safe and intelligent treatment of DUWLs. Methods From September to October 2017, 4 dental units with intelligent water treatment system were selected as the experimental group, and 4 dental units with municipal water as the source of water supply were used as the control group. The microbiological quality of water samples collected from DUWLs was assessed before and after installation of the intelligent water disinfection system in terms of the total viable counts of microorganisms. Student t was used to detect the inhibitory effect of water samples on oral microorganism and its toxicity on human oral normal clone. Results After thoroughly disinfecting the waterlines of the dental unit, the bacteria of dental unit in the control group could rapidly grow up to (3.2±1.02) ×103 CFU/ml within 1 weeks, and the experimental group could be maintained at <100 CFU/ml, the difference was statistically significant (P<0.05) ; In the control group, Pseudomonas aeruginosa, non tuberculous mycobacteria and Acinetobacter baumannii could be detected in the water samples of the control group, while the above pathogens were not be detected in the experimental group. The water samples in the experimental group had significant inhibitory effects on the common bacteria in the dental unit waterlines and in the human oral cavity (P< 0.05) , but only a lower cytotoxicity was shown to the epithelial cells of the human oral cavity. Conclusions The intelligent water treatment system can effectively reduce microbial contamination in dental waterlines and provide safe water for patients. Key words: Disinfection; Dental unit waterlines; Bacterial contamination; Cytotoxicity