The most favored choice of material by patients and dentists alike when filling a cavity is a composite resin that blends with color of your natural teeth. The material is both aesthetically pleasing and highly functional and durable. The material attaches to the tooth structure forming a cohesive bond. Many people have silver mercury colored filling called amalgams which can be unsightly. Since the composite resin is virtually undetectable with the naked eye, many patients choose this material. Cavities damage tooth structure and if left untreated, can cause severe pain and eventually tooth loss.