Particles of mercury can easily bypass simple filters in the dental practice and end up in general water systems. It is estimated that around half of all mercury in waste water is due to dental amalgam. Some of this eventually ends up in a landfill and other sites being converted to a neurotoxin by bacterial conversion. This neurotoxin can end up in fish and then into the food chain, with tuna containing the highest amounts.
Dental amalgam is considered hazardous waste (The Hazardous Waste Regulations), so its disposal needs to be strictly controlled and dental practices need to demonstrate effective disposal and filtering of waste water. For those practices removing or placing amalgam restorations or extracting teeth with amalgam fillings appropriate amalgam waste collection and amalgam separators need to be in place. Amalgam separators need to be fitted and should meet British Standard ‘Dental Equipment – Amalgam Separators’ (BS ISO EN 11143:2000). Amalgam separators may be required for dirty sinks, suction units and dental chairs. Your amalgam waste collector will be able to advise the most suitable format.
Factors to consider are the number of chairs, type of suction and spittoons – wet or dry and also the amount of activity in relation to amalgam removal and placement. It is important to ensure the devices are maintained and monitored according to manufacturer’s guidance. A mercury spillage kit must be available and extracted teeth with amalgam restorations must be disposed of as amalgam waste and not clinical waste to avoid incineration. It is also timely to remember the advice from the Chief Dental Officer who stated that amalgam restoration placement and removal should be avoided in pregnant patients unless in an emergency. In these situations copious water, high volume aspiration and rubber dam are advised.
Whilst amalgam remains a reliable and safe restoration in dentistry, its disposal and the consequent environmental effects remain a serious concern.
