Mercury amalgam fillings aren't just obsolete and unsightly; they might actually be causing harm. When exposed to heat and cold these fillings can expand and contract, allowing bacteria in and causing further tooth decay. That's why at The Center for General and Cosmetic Dentistry, we use only porcelain or composites for cavity and decay restoration. In fact, if you have mercury amalgam fillings, we encourage you to have them removed and replaced. Your smile will be more attractive and healthier, too.