Biofilm and keeping medical water supplies clean

Biofilm is something that we come across every day in and out of the dental or medical practice. It can occur in drains, medical or dental equipment that contains water or on rocks in a stream.

Biofilms form when bacteria adhere to surfaces in a watery environment and begin to excrete a slimy, glue-like substance. A Biofilm can grow rapidly and within a week a large number of bacteria can spread into the waterline.

This growth cycle has four stages.

The first is where the planktonic bacteria or free-floating bacteria adhere to the surface, then Sessile bacteria or anchored bacteria start to secrete. Then the third stage is where the Biofilm develops on the surface and the final stage is where the planktonic bacteria are released from the Biofilm.

Biofilm is found on materials like plastics, metals or medical implants. Biofilms can be formed by a single bacterial species, but biofilms more often consist of many different species of bacteria, as well as fungi, algae, protozoa, debris, and corrosion products. Essentially, a biofilm may form on any surface exposed to bacteria and some amount of water.

Biofilm can occur in dental or medical unit waterlines, because of the long, small-diameter tubing and low flow rates used in dentistry, the frequent periods of stagnation, unused or sporadically used outlets and the potential for retraction of oral fluids. As a result, high numbers of common water bacteria can be found in untreated dental unit water systems.

Health care personnel and patients could be placed at risk of adverse health effects if the water is not appropriately treated, either from the water directly or in the form of spray and mist from the water.

Health and Safety regulations like the COSHH regulations, state that risk assessments must be carried out which will identify favourable conditions for bacteria to grow in the water system.

To control the growth of Biofilm, water supplies can be treated with disinfectants or an Ultra Violet light system. There are many companies who specialise in keeping water systems clean who can supply the relevant chemicals or systems. It is important for you to make yourself aware of the exact instructions for use on all water systems to ensure they are kept clean to safeguard your staff and patients.