Control of cross-infection risks in the dental operatory: prevention of water retraction by bur cooling spray systems.

A new dental unit control system was found to overcome the possibility of mechanically retracting bacteria from the mouth into the water line used to provide a spray of water to cool high-speed burs during treatments. This was demonstrated by results obtained after clinical use and after use in simulated, worst case test conditions using a red tempera indicator solution and indicator bacteria.