Dentists in Singapore will progressively reduce the use of mercury-based tooth fillings, though the material will not be eliminated entirely, as it remains clinically suitable in certain situations.
While tooth-coloured alternatives such as composite resin, ceramic and glass ionomer are now the preferred choice in most cases, dental professionals say amalgam fillings still play a role in modern dentistry.
Dental amalgams, which contain about 50% mercury, have been used for more than 175 years and are valued for their durability and reliability.
Several dentists told The Straits Times that amalgam remains particularly useful for deep cavities and back teeth, where it can be difficult to keep the tooth completely dry during treatment. Unlike resin-based materials, amalgam is less sensitive to moisture during placement.
In November, the World Health Organization (WHO) called for a global phase-out of mercury-based dental amalgams by 2034, citing mercury as one of the top 10 chemicals of major public health concern due to its toxicity. Reducing the use of dental amalgam is also seen as a way to curb environmental pollution caused by mercury emissions.
The Singapore Dental Association (SDA) said the local dental community is aligned with international efforts and is already cutting back on amalgam use while ensuring patients continue to receive appropriate and effective care. Amalgam fillings are now used only in a limited number of cases where they remain clinically indicated.
Dr. Alethea Foong, a prosthodontics consultant at the National Dental Centre Singapore, said dentists select filling materials based on factors such as the tooth's location, cavity size, caries risk and the patient's needs.
She noted that amalgam is still preferred for large, load-bearing back teeth where strength and longevity take precedence over aesthetics, as well as for patients with high decay risk, poor oral hygiene or situations where cost and shorter treatment time are important.
Resin-based composite materials are the most commonly used alternative today, especially for back teeth, due to their natural appearance and acceptable strength. However, Dr. Foong said composites require strict moisture control and are more technique-sensitive, with a higher risk of failure and secondary decay compared with amalgam.
Ultimately, the choice of filling material depends on a dentist's clinical assessment and the patient's individual circumstances, including biting force, allergies to certain materials and existing medical conditions, the SDA said.
Existing amalgam fillings in the population are generally considered stable and safe when properly maintained. A spokesman for the National University of Singapore's Faculty of Dentistry said there is no local data on how many people have such fillings, but international evidence shows that mercury exposure from intact amalgams is low.
Dental amalgams release small amounts of mercury vapour through surface evaporation, corrosion and wear from chewing, brushing and consuming hot food or drinks. Small amounts may also be released during the placement or removal of fillings. However, extensive international reviews have found that exposure levels remain below established safety thresholds for the general population.
Dr. Foong said daily mercury vapour exposure from amalgam fillings is estimated at about 0.5 to 1 microgram per tooth, an amount not visible to the naked eye and comparable to a speck of dust.
She added that large studies in children and adults have found no significant differences in cognitive function or kidney health between those with amalgam and composite fillings over several years, despite slightly higher mercury levels in those with amalgam restorations.
"The level of exposure remains well below occupational thresholds associated with clinical toxicity," she told The Straits Times, underscoring that amalgam fillings, while being gradually reduced, continue to be a safe and useful option in selected cases.
