Dental amalgams—boon or bane?

(Conclusion)

The weight of available scientific evidence favors the safety of dental amalgams as a filling material. Locally known as “silver pasta,” it is actually a mixed alloy of mercury (50 percent), silver (22-32 percent), tin (14 percent), copper (8 percent) and a small amount of other metals.

Its mercury component is what scares environmental and health advocates like Ban Toxics (BT), since high levels of mercury may cause brain, nerve, intestines and kidney problems.

Resolution

In collaboration with the International Association of Oral Medicine and Toxicology-Philippines (IAOMT-Philippines), BT has been pressing the Philippine Dental Association (PDA) House of Delegates to pass a resolution calling for a cessation of the use of dental amalgams on children.

“Let us stop mercury from damaging children’s health and welfare,” Dr. Lillian Lasaten Ebuen,  IAOMT-Philippines president, was quoted in a news release. “Mercury in all its forms is toxic to children, especially because this stage is critical for their brain development and maturation. Moreover, the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) recently confirmed that mercury is a known human carcinogen.”

IAOMT-Philippines and BT jointly submitted a resolution titled “Protecting Children and Sensitive Populations from Dental Amalgam Exposure” to the PDA House of Delegates late last year. But the PDA  is not about to relent to the pressure. I’m not sure if the PDA has come out with an official stand on the safety of dental amalgams as the American Dental Association had done, but on its official website, one can read comments of various dentist-members affirming the safety of silver fillings even on children.

Studies

Stringent, well-designed studies which are conducted by scientists and supported by the United States National Institutes of Health   evaluating the safety of dental amalgams in children showed the same conclusion: “Children whose cavities were filled with dental amalgams had no adverse health effects.”

The researchers noted no detectable loss of intelligence, memory, coordination, concentration, nerve conduction or kidney function during the 5-7 years the children were followed up and closely monitored after they received their mercury-based fillings. The researchers specifically looked for signs and symptoms of damage to the brain and kidneys because these organs are believed to be sensitive to mercury. And their findings have been reassuring to parents.

Dentists will be the first ones to stop using dental amalgams if there is strong evidence which shows its harmful effects, says Dr. Tom Badillo, a practising dentist for more than 30 years. He explains that many Filipinos especially those belonging to the lower socioeconomic classes have moderate- to large-size cavities which are better restored with dental amalgams. He agrees with Dean Vic Medina of the UP College of Dentistry who maintains that dental amalgams are “economical, not technique-sensitive, strong and last longer” compared to alternative filling materials that are “two times more expensive, technique-sensitive and indicated for patients with small- to moderate-size cavities and with good oral hygiene (lower risk for dental caries).”

Dentists’ ally

The dentists may have an ally in the person of the current Philippine FDA director, Dr. Kenneth Hartigan-Go. “I believe (Dean) Vic Medina,” he said in an e-mail when asked to comment on the dental amalgam issue. “Dental amalgam with Hg (mercury) is safe.”

He believes, though, that Philippine dentists should phase down (not stop) its use due to the Minamata declaration. The Philippines is one of the signatories to the 2014 United Nations Environment Program  Minamata Convention on Mercury, which arrived at a consensus to reduce or “phase down” the use of dental amalgams.

Director Hartigan-Go says that the Department of Health (DOH) noncommunicable diseases division and the FDA will review the scientific evidence and come up with concrete action steps.

Pragmatic perspective

Anti-amalgam advocates should look at the issue from a pragmatic perspective. While we should remain wary about high levels of mercury in amalgams—and this is where DOH/FDA regulation may come in (including the disposal of unused amalgams)—banning them totally deprives people of a tried-and-tested treatment for dental caries, which has been used for more than a hundred years. The cost-beneficial and practical benefits of dental amalgams still far outweigh their potential harmful effects.

If we ban dental amalgam completely, it’s like throwing the baby out with the bathwater.