Aerosol Contamination in the Dental Operatory During Oral Prophylaxis: An Occupational Hazard

Aim: To investigate the level of aerosol contamination following oral prophylaxis using ultrasonic scalers at different positions in the dental operatory at different time.

Methodology: In a pre-fumigatedroom of 10m*15m scaling was performed using ultrasonic scalers along with high volume suction while maintaining all aseptic precautions. Blood agar plates were positioned at the level of patient’s chest (P1), doctor’schest (P2), assistant’s chest (P3), on the floor directly below the patients headrest (P4) and 4 feet away from the dental chair at a height 3 feet above the ground (P5) to assess aerosol contamination occurring during scaling procedure. Similarly, blood agar plates were position at P3,P4,P5 for a time interval of 15 minutes after 1 and 3 hours of the procedure respectively to assess the levels of aerosol post procedure.

All the blood agar plates were incubated at 37°C for 24 hours, following which bacterial colony forming unit (CFU) was calculatedfor each plate and gram staining was performed to identify the organism present.

Results: At the time of procedure the patient was most exposed to the aerosol. At the end of 3 hours the percentage of aerosol reduction was 81 %. Gram staining showed that the streptococci were predominant organisms with a few short rods as observed on the plates obtained during the procedure, while gram positive bacilli were seen abundantly in samples obtained at the end of 3 hours.

Conclusion: The study examined the spreading characteristics of aerosol during and after scaling procedure. Even after 3 hours of completion of the procedure some amount of aerosol present in the room. Hence, the dentist must ensure proper precautionary measures to prevent air-borne nosocomial infections.