Effects of waterline flushing and related factors in dental units on bacterial counts in dental water / 대한구강보건학회지

ABSTRACT

Objectives@#Water discharged from waterlines in dental units can cause cross-infection among dental workers and patients by various mechanisms. Therefore, we analyzed the bacterial counts in the water of dental unit chair waterlines, according to waterline flushing and related factors. @*Methods@#A total of 58 dental hospitals located in a metropolitan city participated in this study between September 2019 and January 2020. Water was collected from a high-speed handpiece and a three-way syringe of a dental unit chair and transported to the experimental lab within 4 hours;bacterial plating colony counting was performed after culturing for 72 hours. In addition, a survey was conducted with questions on the characteristics of hospitals, waterline flushing, and related factors, such as water purification systems, regular filter replacement, and backflow prevention equipment. @*Results@#The bacterial count in the water of the dental handpiece and three-way syringe in the institutions that performed waterline flushing was lower than that in the institutions that did not (P<0.001). When waterline flushing was performed on dental handpieces, the bacterial count was found to be lower when regular filter replacement and backflow prevention equipment were combined. In addition, disinfection of waterlines had a significant effect on the bacterial count when performed together with waterline flushing. However, for the three-way syringe, when waterline flushing was performed, no factors significantly affected the bacterial count. @*Conclusions@#To reduce microbial contamination of dental water, flushing of dental unit waterlines combined with regular filter replacement, backflow prevention equipment, and disinfection of waterlines may be effective in dental hospitals.