Continuous ozone treatment as a means to control dental unit water line contamination

Most dental unit water lines (DUWL) harbor biofilms that continually shed planktonic organisms into the water as it flows through the lines. The result is that water used during routine dental procedures is often contaminated above levels allowable for safe drinking water. Many different approaches are being studied to control water line contamination. Ozone is currently being used as the primary means of public water disinfection in over 200 U.S. municipalities; however, its application to DUWL disinfection is limited. The major drawback appears to be the relative short time period that ozone remains active in water, resulting in a lack of residual ozone following treatment. A proprietary system that continuously circulates low concentrations of ozone within DUWL has been developed. The purpose of this study was to evaluate the effectiveness of this system to control the planktonic bacteria found in dental water and to eliminate DUWL biofilm. Following a four dental unit clinical pilot study with various protocols, a lab phase confirmed the effectiveness of ozone treatment. A final 6 dental unit clinical phase tested a potential commercial version of the ozone system. (Abstract shortened by UMI.).