Comparison of antimicrobial efficacy of different disinfectants on the biofilm formation in dental unit water systems using dip slide and conventional methods: A pilot study

Abstract

Objective: Biofilm formation in dental waterlines brings opportunistic infections,especially for immunosuppressive patients. This study aimed to determine biofilm-forming microorganisms by various methods and investigate disinfectants' effects onbiofilm.Materials & Methods: In the study, samples were obtained from the waterlines of10–15 aged six dental units, before (0 min.) and after chlorine dioxide (ClO 2) andhypochlorous acid (HOCl) treatment (1, 5, 10, 20, and 30 min.), and total colonycounts were performed using conventional surface smear method (SSM) and dip slidemethod (DSM). The Congo red agar and Christensen methods were used to examinethe biofilm-forming properties of the isolates. Monitoring of biofilm presence wasalso visualized by SEM scanning.Results: When DSM and SSM are compared in all units where ClO 2 and HOCl areapplied, DSM can detect bacterial growth even during periods of greater exposure todisinfectant application. Although DSM can achieve a value approaching 3% even atthe 10th minute in units treated with HOCl; SSM does not show reproduction at thesame disinfectant exposure and duration; It was observed that in the units whereClO2 was applied, the growth was no longer observed at the 10th minute with DSM,and SSM, 50% growth in the first minute of the units treated with ClO2 could not bedetected in the 5th minute.Conclusions: It is concluded that it can be advisable to routinely disinfect the dentalunit water systems with non-toxic doses of ClO 2 application before patient treat-ments in clinics and also to perform contamination controls at regular intervals withDSM, which is a sensitive and very practical method.