Antimicrobial efficacy of chlorine di oxide vs. distilled water as ultrasonic coolants in reducing aerosol bacterial contamination: A clinical trial

Abstract

Background: Dental procedures such as ultrasonic scaling are known to generate aerosols that contain microorganisms, increasing the risk of cross-contamination and disease transmission, particularly in the context of the COVID-19 pandemic. The use of standard coolants such as distilled water (DW) in ultrasonic devices offers no antimicrobial benefit. Recent advances have proposed chlorine dioxide (ClO2), an oxidative disinfectant, as a potential antimicrobial coolant.

Aim: This study aimedto compare the effectiveness of DW and 1% stabilized ClO2solution (Freshchlor®) as ultrasonic scaler coolants in reducing microbial aerosol contamination during periodontal procedures.

Materials and Methods: A total of 20 patients undergoingultrasonic scaling were divided into two groups: Group 1 (DW) and Group 2 (ClO2). Each patient underwent scaling in a controlled operatory environment. Agar plates were placed at a fixed location near the patient’s chest to collect aerosolized
bacteria during the procedure. The plates were incubated, and colony-forming units (CFUs) were recorded and statistically analyzed.

Result: Group 2 (ClO2) demonstrated a significantly lower CFU count (Mean: 84.0 ± 8.49) compared to Group 1 (DW) (Mean: 149.0 ± 20.19), with the difference being statistically highly significant (P < 0.001).

Conclusion: Using ClO2 as an ultrasonic coolant substantially reduces bacterial aerosol contamination compared to DW, supporting its application in routine dental procedures to improve infection control.

Key words: Aerosols, Chlorine dioxide, Colony-forming units, Contamination, Distilled water, Ultrasonic scaling