When the decay has been taken out of the tooth, it is replaced with “filling” material. In the past, amalgam (silver) fillings were placed into the cleaned out portion of the tooth. Dental researchers are continuing their often decades-long work developing materials, such as ceramics and polymer compounds that look more like natural teeth. As a result, dentists and patients today have several choices when it comes to selecting materials to repair missing, worn, damaged or decayed teeth. These new materials have not eliminated the usefulness of more traditional dental materials, such as gold, base metal alloys and dental amalgam. That’s because the strength and durability of traditional dental materials continue to make them useful for situations, such as fillings in the back teeth where chewing forces are greatest.