Some dentists are still using mercury amalgam for teeth fillings, including in children, according to a new study.
A report conducted for the Environmental Protection Agency found amalgam was more likely to be used when filling people’s back teeth if they were accessing treatment through the Dental Treatment Services Scheme.
The study, conducted by academics at the Cork University Dental School and Hospital, found that while Irish adults have fewer missing teeth, they have more teeth with fillings.
It said that when filling teeth, dentists rely on two main materials: Amalgam, which is a metallic compound containing mercury, and resin composite, which is a plastic, tooth-coloured material. Historically, amalgam was the only direct filling material for restoring posterior teeth.
In 2017, EU regulations set out guidelines, including that dental practitioners should not place amalgam in deciduous or baby teeth, in children aged under 15 years or in pregnant/breastfeeding women.
The regulations also require dentists to have an ‘amalgam separator’ fitted to their chair to minimise the levels of dental amalgam entering wastewater.
Researchers initially sent a questionnaire to a sample of 2,400 dentists obtained from the Dental Register so as to identify any barriers that may exist to the ‘phase down’ of dental amalgam and to find out how dentists manage waste from dental amalgam and other filling materials.
It received 286 responses and found that on average, dentists reported placing 14 resin composite fillings per week. Dental amalgam was the next most commonly used material, with each dentist placing an average of eight amalgam fillings per week.
According to the research, titled ‘A Study on Usage and Waste Management of Amalgam Dental Fillings and Mercury-free Alternatives’: “When asked about deciduous teeth, 15% of dentists reported that they would ‘commonly’ use dental amalgam.
"The proportion of dentists who indicated that they would ‘commonly’ place amalgam in permanent teeth in children aged under 15 years was 33%.
“When asked what circumstances would prompt them to select dental amalgam as the filling material to place in a child, dentists frequently referred to ‘challenges in isolation’, ie, keeping the tooth dry enough to place an alternative to amalgam. They also cited the scenario in which the child is ‘un-cooperative’ or has ‘poor oral hygiene’.”
It also said: “There was a discrepancy between the type of filling material used to fill posterior (back) teeth when the adult patient paid the full economic cost of the treatment (private) and the type of filling material used when the cost of the treatment was reimbursed by the State (Dental Treatment Services Scheme, DTSS).
“In total, 17% of dentists who responded would ‘often/always’ place amalgam in a back tooth in a private adult patient whereas 46% of dentists ‘often/always’ place amalgam in a back tooth in a DTSS adult patient.”
The majority of dentists (94%) who responded had a waste management policy in relation to waste amalgam and only 8% reported they did not have an amalgam separator fitted to their dental chair. A total of 72% did not have a waste management policy for waste resin composite and “there was significant variation in the disposal practices described by respondents”.
However, dentists pointed out that they can only use amalgam when dealing with medical card patients, given how the Dental Treatment Services Scheme is operated by the HSE.
One dentist told the Irish Examiner that the DTSS only reimburses for amalgam restoration on posterior/back teeth and that dentists themselves were likely to be most at risk of any exposure to amalgam.
One dentist also told the Irish Examiner that amalgam is also considered a better material in certain cases by dentists: "The white filling materials are very technique sensitive and do not bond well in any wet situation. So it is very challenging to place an optimum white filling in an uncooperative child when you might not have the ideal circumstances and in that case amalgam is a more forgiving material. It is hard for a non-dentist to understand just how challenging it can be to do dental work for uncooperative children."
She also said there was a place for both materials and added: "The reason it will be discontinued is more environmental than aesthetic based."
Those behind the study also referred to the low sample size used, which equates to less than 2% of the register.