Posts for tag: fillings
Dental amalgam—also known as “silver fillings”—has been used for nearly a hundred years to treat cavities. There are several reasons why this mixture of metals has been the go-to material among dentists: Malleable when first applied, dental amalgam sets up into a durable dental filling that can take years of biting forces. What’s more, it’s stable and compatible with living tissue.
But there’s been growing concern in recent years about the safety of dental amalgam, with even some wondering if they should have existing fillings replaced. The reason: liquid mercury.
Mercury makes up a good portion of dental amalgam’s base mixture, to which other metals like silver, tin or copper are added to it in powder form. This forms a putty that can be easily worked into a prepared cavity. And despite the heightened awareness of the metal’s toxicity to humans, it’s still used in dental amalgam.
The reason why is that there are various forms of mercury and not all are toxic. The form making headlines is known as methylmercury, a compound created when mercury from the environment fuses with organic molecules. The compound builds up in the living tissues of animals, particularly large ocean fish, which have accumulated high concentrations passed up through their food chain.
That’s not what’s used in dental amalgam. Dentists instead use a non-toxic, elemental form of mercury that when set up becomes locked within the amalgam and cannot leach out. Based on various studies, treating cavities with it poses no health risks to humans.
This also means there’s no medical reason for having an existing silver fillings removed. Doing so, though, could cause more harm than good because it could further weaken the remaining tooth structure.
The most viable reason for not getting a dental amalgam filling is cosmetic: The metallic appearance of amalgam could detract from your smile. There are newer, more life-like filling options available. Your dentist, though, may still recommend dental amalgam for its strength and compatibility, especially for back teeth. It’s entirely safe to accept this recommendation.
One of the top concerns in public health today is exposure to the metallic element mercury within the environment. At abnormal levels, mercury can have a toxic effect on our nervous systems and cause other health problems.
These concerns over mercury have also increased attention on one material in dentistry that has included the metal in its makeup for over a century — dental amalgam for filling teeth. Amalgam is a metal alloy that can include, in addition to mercury, silver, tin, and copper. When first mixed dental amalgam is a moldable material used for fillings in prepared teeth. It then hardens into a durable restoration that can withstand biting forces.
While the use of amalgam has declined with the introduction of life-like colored fillings, it's still used for teeth like molars subject to high biting forces. With what we now know about the ill effects of mercury (which can make up to half of an amalgam mixture) is it safe to continue its use?
The American Dental Association has performed extensive research into amalgam safety. They've found that mercury is stabilized by the other metals in the amalgam. This prevents "free" molecules of mercury, the real source of harm to health, from escaping into the blood stream in the form of vapor. Although trace amounts of mercury vapor from the amalgam are released as a person chews, those levels are well below the threshold that could cause harm.
From a patient standpoint, the biggest drawback to dental amalgam isn't safety — it's the appearance of teeth it's used on. Silver fillings aren't considered attractive. And now there are viable filling alternatives that not only look like natural teeth but can withstand biting forces almost as well as amalgam. These materials include composite resins, mixtures of glass or quartz within resin, or glass and resin ionomers. Each of these has advantages and disadvantages depending on how and where they're applied.
After a thorough dental examination, we'll be able to advise you on what filling material will work best to produce the best result. And if we do suggest dental amalgam you can rest assured it will be a safe choice.
If you would like more information on the safety of dental amalgam, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Silver Fillings — Safe or Unsafe?”