Have you been experiencing discomfort or sensitivity in one or more of your teeth? You may be suffering from dental decay that has dissolved the enamel of your teeth, creating a cavity. Dental decay is a serious issue for which a tooth filling is one treatment method used for repair. For over 100 year, amalgam fillings—a liquid mercury and metal alloy mixture—have been used in dentistry to fill cavities caused by tooth decay. If you have had a cavity at some point in your life, there is a good chance that an amalgam filling was used.