A Review of Treatment Methods of Dental Unit Waterlines

Abstract

Dental unit waterlines (DUWLs) are the tubes that connect the high-speed handpiece, three ways syringe and ultrasonic scaler to the water supply. The source of water is either from public water supply or independent water reservoir. The con- tamination of water from DUWLs with micro-organisms was first reported nearly 50 years ago. This issue has resurfaced lately because of an increased awareness of potential occupational hazards and concern about the increasing numbers of immunocompromised patients seeking dental care. Possible ways of transmission of infection from contaminated DUWLs is by aerosol droplet inhalation or open wound contamination in susceptible individuals. Modern methods aiming to reduce DUWLs contamination include: anti-retraction valves and retrograde aspiration of oral fluid, filtration, flushing, using biocides and chemical disinfectants, chlorination, peroxide, ozone and ultraviolet light, independent clean water system, autoclavable systems, electrochemically activated water and drying. Literature review shows that water quality of DUWLs is improved irrespective of the method used but contamination recurs within short period of time if there is no proper maintenance. Search through literature reveals no documented health effects associated with exposure to DUWLs. However, transmission from contaminated DUWLs has been occurred and scientific evidence supports the needs to improve the water quality of DUWLs for better patient care. This paper reviews the biofilm of DUWLs, the available water treatment measures and the recommendations for dental professionals to improve and maintain the quality DUWLs for better patient care and a safer working environment for dental health care personnel.