The term Galvanism (sometimes spelled Galvinism) stems from the work of the Italian scientist Luigi Galvani (1737-1798) and refers to the electrical current produced by the chemical interaction of ions from different metals when they contact each other. In dentistry, dental galvanism occurs when dissimilar metals used in dental restorations come in contact when you bite together and chew or perhaps in utensils striking them as you eat.
Many different metals are used in dental materials. The most commonly known restorations are silver amalgam fillings. While silver is a major component of these restorations, many other metals are included in their composition to enhance strength, stability and ease of handling. Definitive crowns (also called caps) can be made of gold, silver palladium, nickel or other alloys. Provisional crowns, while usually made of acrylic, will sometimes be fabricated from stainless steel - especially in the posterior where excessive attrition may be a concern. Similarly, various metals may be used in silverware.
While Galvanism is normally not an issue between adjacent teeth on the same arch, it often manifests itself when teeth with restorations composed of disparate metals on opposite arches come in contact on chewing or simply when you bring your teeth together in biting down. While this is a rare occurrence, you will find it quite striking should it happen to you. Patients often liken the sensation of Galvanism to chewing on tin foil or, in more extreme cases, like experiencing the electric shock that it actually is. The current produced in dental Galvanism is propagated through the restoration in question directly to your tooth's nerve. While it is not a serious situation with long term health consequences, it is a quite unpleasant and aggravating sensation that you would not tolerate for long.
When a silver amalgam filling contacts... ... a gold one in your bite, galvanism can result.
Fortunately, when Galvanism occurs, it is quite easily rectified. Often times, Dr. McArdle can make a slight adjustment to one of the restorations involved so that contact with your opposing tooth falls on the natural tooth structure around the filling concerned. Occasionally, you will need to have a replacement situated with another kind of material or type of restoration. In the case of two crowned teeth touching in your bite as the offending circumstance, one or the other will need to be replaced. This, however, has been extremely uncommon in Dr. McArdle's experience as he has never personally had to replace a crown because of Galvanism and only heard of a few other dentists that he knows having to do so. This is because more crowns than not that are made with metals have porcelain baked onto them for esthetic purposes and those that are all metal for areas where your bite might predispose overlying porcelain to fracture are customarily made of gold and so are compatible with each other. If a stainless steel provisional crown is the culprit, it can be remade with acrylic or other temporary materials to resolve this issue. If silverware is the cause, avoiding the sensitive tooth will solve the problem. If you have any questions about Galvanism or suspect that you may be suffering from it, please speak with Dr. McArdle.