Posts for tag: fillings
Over the last century and a half millions of people have had a tooth cavity filled with “silver” amalgam. Perhaps you’re one of them. The use of this effective and durable filling has declined in recent years, but only because of the development of more attractive tooth-colored materials.
At the same time there’s another issue that’s been brewing in recent years about this otherwise dependable metal alloy: the inclusion of mercury in amalgam, about half of its starting mixture. Various studies have shown mercury exposure can have a cumulative toxic effect on humans. As a result, you may already be heeding warnings to limit certain seafood in your diet.
So, should you be equally concerned about amalgam fillings — even going so far as to have any existing ones removed?
Before taking such a drastic step, let’s look at the facts. To begin with, not all forms of mercury are equally toxic. The form causing the most concern is called methylmercury, a compound formed when mercury released in the environment combines with organic molecules. This is the form certain large fish like salmon and tuna ingest, which we then ingest when we eat them. Methylmercury can accumulate in the body’s tissues where at high levels it can damage various organ systems.
Dental amalgam, on the other hand, uses elemental mercury. Dentists take it in liquid form and mix it with a powder of other metals like silver, tin and copper to create a pliable paste. After it’s placed in a prepared cavity, the amalgam hardens into a compound in which the mercury interlaces with the other metals and becomes “trapped.”
Although over time the filling may emit trace amounts of mercury vapor, it’s well below harmful levels. You’re more likely to encounter “un-trapped” mercury in your diet than from a dental filling. And scores of studies over amalgam’s 150-year history have produced no demonstrable ill effects due to mercury.
Although it now competes with more attractive materials, amalgam still fills (no pun intended) a necessary role. Dentists frequently use amalgam in less visible back teeth, which encounter higher chewing pressures than front teeth. So, if you already have an amalgam filling or we recommend one to you, relax — you’re really in no danger of mercury poisoning.
For over a hundred years dental amalgam — a combination of silver, mercury, tin and other metals — has been an effective filling material for teeth damaged by decay. But it has one major drawback — its metallic appearance stands out in stark contrast to the natural color of teeth.
As an alternative, composite resin fillings can match the color, shape and texture of natural teeth. These materials and the techniques used to bond them are proving just as effective as and more aesthetically pleasing than dental amalgam.
Fillings help protect and preserve a decayed tooth. By first removing decayed tooth structure through drilling, the resulting void is filled with durable material that strengthens the tooth and provides it protection from further decay.
The ultimate goal for restoration is to return the tooth to as near normal form and function as possible. Dental amalgam serves well in terms of function, providing the tooth strength in the face of the daily biting forces it encounters. In contrast, composite resins excel in appearance, but haven’t always matched the durability of amalgam. They’re material construction has improved over time, though, as well as the techniques used to bond them to teeth.
Most of these bonding techniques incorporate layering. The first step is to seal the dentin (the porous, living tissue just below the enamel); we then build up the composite material layer by layer within the tooth using special bonding adhesive and curing lights. In some cases where a large volume of tooth structure must be replaced, the restoration is first formed on the tooth and then removed for curing before being cemented into the tooth or a separate restoration is formed by a dental lab.
The end result is a tooth which both looks and functions like a fully intact tooth. Though care must be taken not to subject composite resin restorations to undue forces (no cracking open nutshells, for example), your new filling should continue to serve you and look great for a long time to come.
If you would like more information on metal-free restorations, 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 “The Natural Beauty of Tooth Colored Fillings.”