In very general terms there are four kinds of fillings: silver amalgam (grey color), gold (gold color), composite resin (white) and ceramic (white). Silver amalgam when set is a solid metal mixture of primarily silver, mercury, copper, and tin. Gold fillings are a solid metal mixture of primarily gold and small amounts of silver, copper and palladium. Composite resin is a mixture of an organic resin with an inorganic filler of quartz or glass. Ceramic fillings are composed of ceramics. The best type of filling will depend on which tooth is filled, the filling size and location on the tooth. It also depends on the patient’s goals such as appearance, how long the filling is desired to last, how well the filling should work and of course, cost.