In recent years there have been more and more incidents of infection from dental facilities, specifically from the water coming from dental lines containing pathogenic bacteria. The EPA mandates drinking water standards for public water supplies and most dental offices are supplied public water, so the water is of certain quality. Under the Safe Drinking Water Act, the EPA recommends a level of 500 Colony forming Units per milliliter (CFU/ml) of heterotrophic bacteria. The EPA’s SDWA requires testing for total coliform and E.coli and heterotrophic bacteria which are non-coliform are not typically required but used as an indicator for disinfection processes. That is why the CDC recommends testing for dental lines for Heterotrophic Bacteria to determine if disinfection processes are keeping the dental lines clean enough. In 1995 the American Dental Association took a stricter standard and recommends that dental line have less than 200 CFU/ml of heterotrophic bacteria at any point within the dental lines. The ADA also has specific recommendations for water treatment and other measures to reduce bacteria build-up and reduction of bacteria that patients are exposed to in the water used.
Bacteria of Concern
There are a couple of bacteria that can be of greater concern, especially for patients that have weakened immune systems. Legionella is of concern, because it likes to live within the biofilms which are developed in dental lines. There have been some cases of legionella which have been linked with dental visits. Pseudomonas aeruginosa is another bacteria that is considered an opportunist pathogen, which means if an opportunity exists such as a cut or weakened immune system this bacteria can cause illness.
Water used in dental surgeries where the risk is greater for infection due to open tissue. The ADA recommends using sterile water, which are required to have low heterotrophic plate counts. Water should be dispensed in disposal containers to further minimize bacteria contamination as most dental water equipment cannot meet this strict heterotrophic bacteria levels.
Boil Water Advisories
There are more and more boil water advisories that are happening due to water main breaks. Water main breaks are increasing due to the age of infrastructure and extreme weather patterns. When there is a boil water advisory in your area, do not use any water coming from the public water supply. Bottled water should be used for patient rinsing. Additionally the public water should not be used for diluting germicides or for washing hands, unless water has been boiled.