Disinfection effect of slightly acidic electrolyzed water on Dental unit water lines

Abstract

Objective To explore the disinfection effect of slightly acidic electrolyzed water on dental unit water lines (DUWLs). Methods First, a total of 5 dental chair units (DCUs) with self-contained water supply were selected and were placed with freshly slightly acidic electrolyzed water (SAEW) every night. And then, we collected water samples from dental handpieces and water outlet of the gun for three purposes at 8 am and 12 am of the next day to count bacterial colony. This research included four stages involving that the content of effective chlorine of SAEW was about 40 mg/L with 20 days for continuous disinfection, the content of effective chlorine was about 20 mg/L with 10 days for continuous disinfection and 7 days for stopped disinfection, the content of effective chlorine was about 10 mg/L with 15 days for continuous disinfection. Results The average pass rates of water samples were 99.25%, 98.00%, 98.33% with SAEW of three different concentrations for the disinfection of DUWLs. The pass rate of water quality was changed from initial 100% to 0 without disinfection for water lines for 7 days. Conclusions There is microbial contamination in DUWLs. The disinfection effect is remarkable with SAEW for DUWLs, and there is no significant difference among DUWLs of different concentrations. Therefore, SAEW with low concentration of effective chlorine can be applied in clinic for continuous disinfection of DUWLs with self-contained water supply by taking all factors (disinfection effect, safety of dental treatment instruments, degree of comfort of patients and so on) into account. Key words: Disinfection; Slightly acidic electrolyzed water; Dental chair unit; Dental water lines