Efficacy of preprocedural mouth rinsing in reducing aerosol contamination produced by ultrasonic scaler: a pilot study.

Background: The aerosol generated by an ultrasonic scaler contains microorganisms that can penetrate into the body through the respiratory system of dental surgeons and patients. The aim of this pilot study is to evaluate and compare the efficacy of commercially available preprocedural mouthrinses containing 0.2% chlorhexidine gluconate, an herbal mouthwash, and water in reducing the levels of viable bacteria in aerosols.

Methods: This single-center, double-masked, placebo-controlled, randomized, three-group parallel design was conducted over a period of 45 days. Twenty-four patients with chronic periodontitis were divided randomly into three groups (A, B, and C) of eight patients each to receive 0.2% chlorhexidine gluconate, herbal mouthwash, and water, respectively, as a preprocedural rinse. The aerosol produced by the ultrasonic unit was collected at patient's chest area, doctor's chest area, and assistant's chest area on blood agar plates in all three groups. The blood agar plates were incubated at 37°C for 48 hours, and the total number of colony-forming units (CFUs) was counted and statistically analyzed.

Results: The results showed that CFUs in groups A and B were significantly reduced compared with group C, P <0.001 (analysis of variance). Also, CFUs in group A were significantly reduced compared with group B, P <0.05 (independent t-test). The numbers of CFUs were highest at the patient's chest area and lowest at the assistant's chest area.

Conclusion: This study suggests that a routine preprocedural mouthrinse could eliminate the majority of bacterial aerosols generated by the use of an ultrasonic unit, and that 0.2% chlorhexidine gluconate is more effective than herbal mouthwash.