CDA Essentials 2019 • Volume 6 • Issue 6

38 | 2019 | Issue 6 Human error and lack of compliance with disinfection protocols can also promote formation of biofilms. For example, some disinfection systems require the addition of tablets or liquid each time the water reservoir is refilled. If this step is omitted, biofilm will grow unimpeded. In addition, there is a risk of contamination from the operator’s hands each time the water bottle is removed, unless the user is diligent about not touching the inner surface of the water bottle or the pick-up tube used for water uptake. Strategies to Maintain Optimal Quality Water in DUWL 1. Follow chair manufacturer’s instructions for use (MIFU). If there are no instructions for waterline maintenance from the manufacturer of the dental unit, contact the manufacturer to request the MIFU. Both Health Canada and the FDA in the United States require manufacturers to supply these instructions, which are also known as “labelling.” When buying new equipment, always get MIFUs prior to purchase to ensure that the instrument, device or equipment is right for your office. 2. Use an optimal water source. Monitor or test the quality of source water. Suitable water quality is defined as having a CFU/ml (colony-forming units per millilitre) as low as possible and not more than the 500 CFU/ml † standard for drinking water. 2 Although water can be provided from a municipal source, this is not recommended (see Intermittent Disinfectants p. 39). When choosing a water source, consider other factors that could affect water quality, such as the way the water is piped, stored and transferred from the source to the dental chair. 3. Clamp off any dead legs in dental chair waterlines. Dead legs in plumbing are areas that are non-functional but not capped off, where biofilm grows unimpeded and contaminates the rest of the water supply. Have a knowledgeable technician clamp dead legs off in all dental chairs. 4. Flush waterlines prior to the first session of the day and between patients. Lines should be flushed at the start of the treatment day and between each patient; each waterline that was used during patient care should be flushed for at least 20 seconds to remove suck back. Lines that have been S upporting Y our P ractice Infection Prevention and Control at the Dental Office An ongoing water quality monitoring program ensures that quality is maintained in all lines and that reductions in water quality can be treated quickly and appropriately. ➜