This restoration consists of a combination of metal elements that combine into silver-colored filling material that is hard like tooth structure. This material is used in primary teeth and some permanent teeth due to fracture and wear resistance. On permanent teeth it is indicated when a composite restoration may not adhere to defective tooth structure. As with other restorative materials, new decay can start on another part of the tooth, or even underneath an old filling. Good oral hygiene and a diet low in sugar are important to increase the longevity of the filling. It is also important to avoid eating very sticky/tacky candies which can pull a filling out, and avoid chewing on hard candies or ice which can crack a filling.