With all the information appearing in the press recently about biofilm in the water lines, our patients should feel comforted in the fact that all of our dental units use a self contained water system. The water that is used in this system has been distilled to kill bacteria and remove minerals. Additionally, all water lines are purged daily and disinfected weekly. The protocol we used was developed by the US Air Force and as off November, 1998 was in use in over 80% of all Air Force dental units. This system of independent water and a disinfection protocol gives our patients the best possible degree of safety.