Waterlines and water delivery systems in your dental units can quickly become contaminated with bacteria and other microorganisms thriving on the tubing, in handpieces, and in air/water syringes, then delivered to your patients during treatment. The bacterial colonies exist as part of the biofilm, securing themselves to the solid surfaces and creating bacterial loads exceeding 100,000 CFU/mL (colony forming units/milliliter). In 1995, the ADA panel on dental unit waterlines recommended that all manufacturers of dental equipment ensure that water delivered for nonsurgical treatment contain less than 200 CFU/mL. Current CDC recommendations are that water for nonsurgical treatment in dentistry meet drinking water standards and contain no more than 500 CFU/mL. Water for surgical treatment including open flaps, incisions, and excisions must be sterile. This includes ultrasonic periodontal scaling under open flaps with sterile irrigation solutions. Bacteria in your tubing and equipment are heterogeneous and may have survived public utility disinfection prior to delivery. Gener-ally, these microorganisms do not cause disease, but some bacteria, such as Pseu-domonas aeruginosa, Legion-ella species, and aquatic, nontuberculous mycobacteria can be retracted into your waterlines and released during dental treatment. Also, endotoxins, which are created as part of the cell wall of Gram-negative bacteria found in dental water systems, can cause shock, fever, respiratory distress, and increased heart rate. High levels of endotoxins can affect healing after periodontal surgery, and increased levels of endotoxins from aerosols may cause asthma in dentists. Hygienists using ultrasonic scalers may be at increased risk as well due to aerosols and spatter of plaque and bacteria. Since the ADA panel on waterlines raised the awareness of professionals in the industry in 1996, products are now available to assist in controlling or eliminating biofilm contamination. These include independent water reservoirs; chemicals and germicides to inactivate or remove biofilms, such as chlorhexidine gluconate, alkaline peroxide, chlorine dioxide, and alcohol; antimicrobial reservoirs and tubing; bottled water systems; and factory-installed water treatment systems.
(Source: Dimensions of Dental Hygiene, June 2007)
