Evaluation of bacterial aerosol contamination during dental procedures

Introduction: Bio-aerosols are airborne particles that contain bacteria, viruses and fungi, or originate from living organisms, which possess potential for transmitting infections in healthcare settings including dental clinics due to their ability to lodge in the smaller air passages of the lungs. Many dental procedures that use mechanical instrumentation have the potential to create contaminated aerosols and splatter. These aerosols represent an infection hazard to the dental team and other patients due to their gross contamination with microorganisms and body fluids. Objective: The purpose of the present study was to evaluate the bacterial aerosol contamination during dental procedures in the dental operatory. Materials and Methods: 60 patients with mild to moderate gingivitis attending outpatient department of Periodontics were included after obtaining consent. Settle plate method employing 10% sheep blood agar plates was used to collect the aerosols at three standardized locations. The sampled blood agar plates were transported immediately to the Department of Microbiology for: Identification of bacterial colonies as per standard procedures. Counting the number of colonies formed on blood agar plates using colony counter unit. Results: Alpha hemolytic Streptococci (81.67%) were the predominant bacteria isolated followed by Micrococcus (38.89%). Staphylococcus aureus was isolated in 30% among which 10 isolates (18.5%) were methicillin resistant. Plates placed on the patient's chest area showed highest mean colony count of 105.3 CFU/ plate, plates on dental tray showed 68.38 CFU/plate and plates placed 6 inches away from patient's mouth showed 40.12 CFU/plate. Conclusion: To minimise the risk posed by dental aerosols it is imperative to implement control measures aiming to reduce the generation and exposure to microbial aerosols in dental clinics.