In the past, traditional silver amalgam with a large mercury content was placed routinely. They still constitute the majority of restorative dentistry performed in dentistry today. With an increasing number of progressive dental practices, dental offices are beginning to leave this type of restoration in the past for a number of reasons.
- Toxicity- There is a significant controversy today about the mercury in the amalgam filling material. Mercury is a toxic poison and although still accepted by organized dentistry, we cannot see a good reason for placing a mercury-containing restoration when today’s alternative materials outperform silver fillings without the potential risks of mercury.
- Tooth Damage- Non-precious metal fillings corrode (rust) in the wet environment of the mouth. Over time, this inevitable corrosion causes serious expansion of the filling material, resulting in stress and fracture of the previously strong and healthy surrounding tooth structure. In simplest terms, silver fillings eventually “crack” the teeth they are placed in.
- Cost- The inevitable corrosion of silver fillings and the eventual fractures we see necessitate extensive treatment to restore the affected teeth. Although initially cheaper to place, a silver-mercury filling may be the most costly way to restore a tooth in the long run.
- Esthetics- Silver fillings initially look unnatural, and after their expected corrosion they are downright ugly. Today’s bonded alternative materials blend into the teeth and give patients the natural esthetics they expect and deserve.
Mercury-free dental restorations, such as composites and glass ionomers, offer many advantages:
- Environment-friendly: Composites and glass ionomers are mercury-free, and there is no evidence of environmental toxicity.
- Preserve teeth: The WHO report Future Use of Materials for Dental Restoration states that “Adhesive resin materials [like composite] allow for less tooth destruction and, as a result, longer survival of the tooth itself.”In addition to preserving tooth structure, composites can strengthen and enhance biomechanical properties of the restored tooth.
- Prevent caries: Glass ionomers have properties that are known to help prevent tooth decay. Composite placement can also incorporate preventive measures, including sealing of adjacent pits and tooth fissures.
- More accessible: Glass ionomers, used in atraumatic restorative treatment (ART), have proven valuable in certain clinical situations where they can be more accessible and less expensive than amalgam (for example, in communities without electricity).
- User-friendly: it has been shown that the time needed to carry out a Hg-free [mercury-free] restoration has reduced significantly as dentists have gained more experience in the handling of Hg-free materials so that there is currently no (or minor) time difference to perform Hg-free restorations compared to amalgam.