An extensive study provides insights into the efficacy of two disinfection techniques utilized in inactive dental chair units’ (DCUs) waterline systems. The researchers involved in this study conduct an on-the-spot sampling and quantitative bacterial analysis to gauge the efficiency of chlorine-based disinfectants versus a combination of multi-enzymatic detergent with hypochlorous acid in controlling microbial contamination in these waterline systems. The study does not discern any significant divergence in disinfection efficacy between the treatment and control groups following disinfection or on the third day post-disinfection. However, marked differences were observed on the fifth and seventh day post-disinfection.
Chlorine-based disinfectants and the combination of multi-enzymatic detergent with hypochlorous acid appears effective in managing contamination within three days of inactivity in waterline systems. However, when the period of inactivity extends beyond five days, the latter combination demonstrates its superiority by reducing biofilm adhesion over time.
A critical component of the DCU, the dental unit waterline – composed of interconnected plastic hoses and metal control valves, can become a hotspot for microbial growth and biofilm formation when left inactive. This issue arises from specific circumstances such as limited patient appointments, altered clinician schedules, or simply, an overflow of inactive DCUs due to rapid practice expansion. This highlights the importance of appropriate chemical disinfectant selection and emphasizes the role of continuous disinfection strategies in controlling waterline contamination.
The researchers chose 45 inactive DCUs from a tertiary Class A stomatological hospital in Hubei Province for this evaluation with the DCUs randomly assigned to either the chlorine-based treatment group or the multi-enzymatic detergent/hypochlorous acid disinfectant control group. Additionally, experimental design incorporated a blank control group for rigorous methodological assessment. Trained full-time nurses performed disinfection procedures weekly with sample collection conducted before disinfection and on successive third, fifth, and seventh day post-disinfection.
In conclusion, the study proves the relevance of both tested disinfection methods in a short-term perspective. However, for inactive periods exceeding five days, the multi-enzyme detergent and hypochlorous acid disinfectant take the upper hand in maintaining waterline hygiene in DCUs, thus supporting the selection of optimal disinfection methods in inactive DUWLs.