Airborne contamination of the dental operatory during activities performed with open or closed windows.

Purpose: To quantify the biological contamination of a dental operatory environment using a biological tracer.

Methods: A Streptococcus mutans suspension was infused into the mouth of a phantom, and an operator performed standardized dental procedures using an air turbine, a contra-angle handpiece, or an ultrasonic scaler either with windows open or closed. The presence of the tracer was measured by placing Petri dishes with a selective medium at 18 sites on the dental unit and 38 sites in the surrounding operatory environment.