What is the problem with dental amalgam?

-the truth about black fillings once for all-

Last week a woman walked in my office. Data protection and all- I can’t give out ger name. So, we will call her Maria.

I examined Maria and happily exclaimed that her teeth are perfectly healthy and that we will see each other in a year. I spiced it up with some praising of her oral hygiene (I know flossing is a pain to many people, and I always take time to point it out whenever I meet someone really putting a lot of effort).

Normally all my customers love this sentence. That means they did a great job. That means they don’t have to make extra appointments. That means they get to save some money…
But she frowned.
It was curious.

“But how about those black fillings? You see, I want to get pregnant and I am afraid my baby will not be healthy because of them. Shouldn’t we replace them?”

Maria is neither the first nor the last one to ask me this. So, I will tell you what all the Marias of this world have the right to know: what is this metal filling, why does it have the bad reputation, when should we (not) remove it and what is the best material to replace the amalgam.

What is Amalgam?

Amalgam is a material for tooth-fillings that looks metal-grey. This typical color comes from various metals present in this material. There are several types of amalgam, but basically, they are all alloys made of silver, tin and copper combined with mercury, where mercury is approximately 50% of the weight.

Amalgam has been used as a material for filling carious defects for more than 150 years and, according to the American Food & Drug Administration (FDA) hundreds of millions of patients worldwide received amalgam fillings so far.

If placed properly, amalgam fillings are stable and long lasting. They rarely break and typically remain in your mouth for 10 or more years. We know this from many decades of research and clinical experience. Working as a dentist in Austria, Germany and Serbia, I saw many people with old but healthy amalgam fillings in their mouth.

The first thing we notice about amalgam filling is that it is black. This can be very noticeable when we laugh, especially if someone has a wide smile. It is only understandable that this ugly material is not very popular in 21st century and filter-esthetics culture.

Additionally, amalgam is not bonded to the tooth. That means it has to fit mechanically, like a puzzle. In order to provide the necessary form for the amalgam, dentist has to remove much of the healthy tooth substance. In modern dentistry, we don’t have to waste the natural tooth substance any more, and prefer saving the tooth as much as possible using new filling materials instead of amalgam.

But all this is not the main reason amalgam gained the bad reputation.

Is amalgam dangerous for your health

Practically from the very beginning of its use, we saw accusations that amalgams were poisoning the patients, causing autism, diverse neurological disturbances and many more things. Those derive mostly from non-scientific journals, but occasionally such information could be read in scientific sources as well.

Nonetheless, extensive reviews of all available research on amalgam show there is no evidence that amalgams are harmful for adults. The official statements of World Health Organization (WHO), US Food & Drug Administration (FDA) and many other notable bodies confirm this. German Association for dental, oral and joint health (DGZMK) also says that every filling material has its own advantages and disadvantages, but that none of the currently used (including amalgam, s. below) is highly problematical.

And yet: on March 14 2017, The European Parliament published a document which forbids the use of amalgams for treatment of deciduous teeth, in mouth of children younger than 15 years of age, as well as in pregnant and breastfeeding women (Exception is allowed in a case where this is deemed necessary by the therapist concerning patients’ special medical needs).

So, if the amalgam in our mouth is not harmful, why this regulation?

If the amalgam fillings are not dangerous for me, why does EU Parlament forbid its use for kids and pregnant women?

The story goes far back to 1956, to a Japanese city Minamata on the Yatsushiro Sea, when a patient came to the hospital having an unknown set of neurological symptoms. And he was not alone: he was followed by an outbreak of patients with similar symptoms until doctors realized the cause was poisoning of these people by hard metals, particularly methylmercury. This sickness got the name Minamata disease, but where did the poison come from – this was the second puzzle.

It took 10 years to explain how this poisoning happened. Turned out, a local factory was releasing the waste containing hard metals direct in the sea. Through the food chain, methylmercury was further accumulated in fish and shellfish, consequently poisoning the inhabitants of the surrounding coast who were naturally consuming a lot of seafood.

By 2001, 3000 Minamata disease patients coming from the same region were reported. According to various listings, more than 1400 of those patients died of the consequences.

These hazardous happening, as well as many other events reported worldwide raised the consciousness about environmental issues related to hard metals. This caused a global movement to protect human health and the environment from the adverse effects of mercury.

50 years later (!!) the European Parliament published the rules that control the mining, production and disposal of hard metals- generally a set of guidelines to control use of hard metals and their release in the environment. Of course, completely eliminating the pollution will be a process that takes many decades. But even the longest travel starts with a single step.

How does Amalgam fit in this story?

Amalgam contains mercury which is a hard metal.

Once placed in you mouth, mercury in your filling is inactive and you are not swallowing it. However, once this filling has to be replaced (because it broke, because the edges are not sitting tightly any more, because a new caries developed), the complete amalgam has to be removed. During the removal of amalgam dental assistant will typically hold a suction system right next to your tooth in order for you not to swallow or inhale bits of metal. For many decades this suction system on the dental chair brought the amalgam waste direct into water, where small quantities of it continuously poisoned our environment. Today some dentists (but not all!!) also have amalgam separators: special containers in which amalgam particles land in, so we can specially dispose od them without sending the particles to environment with wastewater. But not everyone has such equipment, and this means that as long as there are amalgams to be replaced the environment is being jeopardized.

Furthermore, in order to reach your mouth, the mercury for amalgam first must be mined, then fabricated into useful material form and then packed in the amalgam capsules. All those steps inevitably produce some waste and add to pollution.

You understand now, it is not the health of individual we are fighting for with all these anti-amalgam measures. It is the health of our planet, of humans, animals and plants alike.

But amalgam is a cheap filling and, unfortunately, Austrian public insurance system neither takes dental developments from last 60 years nor environmental importance into consideration. Luckily, stopping the use of amalgam in pregnant women and kids is not the end of the fight. The elimination of metylmerculy (and amalgam) will occur in 2 phases.

1. In the phase-down (currently happening) we are trying to reduce the fabrication and waste of hard metals (including amalgams. That is why amalgam is now forbidden for pregnant women and kids).
2. In the phase 2, so called phase-out, all EU countries will be forced to eliminate amalgams. This is expected to happen with the next announced revision of the document 2022 (though the commission may decide to prolong the elimination)

Austria will have to comply with European Parliament policy when the phase 2 starts, and we may join Norway, Denmark, Sweden, Island and Finland who already fight this environmental malpractice with no amalgam use.

Until then, it is the responsibility of each of us to give our own contribution to healthy environment.

Ok, the next time I need a filling It will not be amalgam. But should I remove the existing amalgam fillings?

My rule of the thumb here is the following: if your filling has tight edges, causes no pain and we can see no caries around the margins or beneath it- there is no reason to replace it. There are two reasons for this:

1. with every filling replacement, dentist has to remove a part of heathy tooth in order to bond the next filling to it

Additionally, amalgam removal may expose you to the vapor containing mercury. Inhaling (not so much swallowing!) these is more dangerous than having the inactive amalgam filling in the mouth.

There is one exception to this rule:

If you know or believe you have allergy or sensitivity to any of the metals present in the alloy (mercury, silver, copper, tin), you should make a dental appointment online and  discuss the therapy options with your dentist.

Koje alternative za amalgam postoje?

If the caries on your tooth is small, the best approach is to restore it using a composite. This filling material comes in various tooth shades and allows us to work saving the natural tooth substance as much as possible. Unfortunately, Austrian dental insurance does not cover the cost of this solution although it has been golden standard for decades worldwide and a patient has to bare the costs alone.

Lately there is a cheap filling material on the market that is not as beautiful as composite, but still white-ish and strong enough to be used not only as temporary but as a definitive filling material. This material is called Cention and I hope social insurances will take it into consideration instead of Amalgam.

Finally, if the defect is big your dentist will consider making an inlay, onlay or a crown. Those can be made of pure ceramics, which is known to have best biocompatibility. Ceramic restorations look perfectly natural and last long because they are strong. Traditionally, ceramic crowns are made in 2 or more sessions, but today you would receive your ceramic inlay/ onlay/ crown/ veneer in one session.

There are also materials that are only intended as temporary dental fillings, such as glass ionomer cements. In low income countries they are sometimes used as a definitive filling material, but according to ISO standardisation they are definitively not strong enough to withstand the chewing forces and dentistry does not recommend them

The approach of our office: do more for the environment than the law makes you do

I don’t place amalgams in my office. Instead, my patients receive a composite restoration that is the golden standard today (Bonus: for the composite filing I use only locally produced materials of a renown dental producer, in order to reduce the ecological imprint and maintain high standard for my patients).

When removing the amalgam, we use strong suction systems (those are placed directly next to the filling being removed and prevent vapor being inhaled) and the dental chair that has the option of integrating amalgam separator.

Sometimes additional placing a rubber dam is also possible, but this strongly depends on the situation in mouth ans is not always possible.