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Putting it All Together – Checklist for Dental Unit Water Quality Improvement

Understanding the regulatory framework for devices and products intended to improve water quality is part of the product selection process. A comprehensive approach to improved water quality also includes proper selection, use maintenance, and monitoring of all equipment, devices, and products. Use this checklist to help ensure the quality of dental water.

The basics

• Contact the dental unit manufacturer to request recommendations for treatment and maintenance
• Select products that are intended for dental waterline treatment rather than household products or disinfectants
• Use clean (tap or distilled) source water as recommended by the manufacturer of the treatment product and the dental unit, they should not contradict each other
• Routinely clean independent water bottle according to manufacturer's instructions
• Provide training to all personnel in how to properly replenish, treat, test or otherwise manage the bottled water systems

Treating waterlines

Always follow the manufacturer's instructions for the use of chemical products or devices to treat waterlines. Several best practices will help you ensure good results:

• Always wash hands before handling water bottle to prevent inadvertent contamination from hands
• Change microfilter cartridges according to the manufacturer's stated time interval
• Do not use products for continuous use as coolant water to handpieces or other dental patient care devices unless specifically indicated on the product label or insert
• Use shock treatment initially if the dental unit has not been reliably treated or tested previously, and as indicated by the waterline treatment product manufacturer
• If the manufacturer does not indicate a time interval for shock treatment, periodically monitor water quality to determine if additional treatment is necessary

Testing waterlines

Current recommendations indicate that quarterly testing of dental units ensure the best results of water quality. The frequency depends on the type of treatment and the history of the office regarding levels of contamination despite the use of treatment methods. Best practices for testing include:

• Test water immediately before scheduled treatment
• Wash hands before collecting sample
• Take care to not contaminate inside of water collection bottle
• Follow the test manufacturer’s or test lab’s directions for storage and transportation to testing facility
• When performing tests in-house ensure the use of proper sampling media, incubation times, and temperatures. The scientific literature suggests that in-office testing results are less reliable than those performed in a qualified water testing laboratory.
• Neutralize chemicals in tap water that will interfere with sample growth (sodium thiosulfate is one type, check with test kit instructions)
• Maintain a record of sampling results for the same period of time that you keep spore test results
• Use sampling results to establish reasonable schedule for future sampling (i.e., if monthly testing for a year results in no waterlines exceeding 500 CFU/mL, consider testing every other month or quarterly)


Q: We are using a dental waterline treatment that goes in the bottle attached to our units. How do I know that it actually makes the water meet the 500 CFU/mL goal in the CDC guidelines?

A: The only way to ensure that the product is producing the desired effect is to monitor the water quality. There are several reasons that water quality may remain poor despite the use of a product intended to treat dental waterlines. These can include failure of the product, failure to provide initial "shock" treatment if required, improper use of the product, or contamination of the water bottle. There are several companies that offer water-testing kits, including some university dental schools. It is important to follow the instructions carefully for water quality testing. For suggested frequency of water quality testing, consult the manufacturer of either your dental equipment or the water treatment product.

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Last Updated on Wednesday, March 02, 2022 02:15 PM