Dental unit waterlines: Approaching the year 2000

Background. This article discusses biofilm formation in dental unit waterlines and its resulting potential health effects. It also provides a review of ongoing research and available means to reduce microbial contamination in dental unit water. Methods. An expert panel was convened by the American Dental Association Board of Trustees to discuss the implications of biofilms in dentistry. This report summarizes the panel's conclusions. Conclusions. The dental profession must continue its awareness of the presence of high levels of opportunistic microorganisms in dental unit water. Despite the lack of evidence of adverse health effects related to these microorganisms, they have the potential to overload the defense systems of immunocompromised patients and occupationally exposed dental staff members. Steps should be taken to improve dental unit water quality; contact of a patient's open wound, mucous membrane or body cavity with water of poor microbiological quality simply is inconsistent with patient expectations of modern dentistry. Efforts should continue to evaluate the health implications of biofilms in dentistry as new technology, research and data become available.