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.
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.”