In the past, teeth were filled with a mixture, or amalgam of different metals. Today, that is changing, as more natural looking and metal free dental fillings are becoming the preferred approach. Metallic fillings, or amalgams, could not bond with the tooth. They acted merely as a filler that provided a degree of protection for the tooth. Modern tooth colored fillings, or resin based composites, use the surface of the tooth to create a bond that is stronger and more protective for the teeth. In addition, they are more esthetic and tend to require less of the tooth to be removed for them to be placed. Amalgam fillings were used due to its strength and rigidity. However, these rigid materials actually contributed to corrosion and possible fracture of the underlying tooth structure. Composite fillings not only uses natural tooth as a guide for its form and function, but also for its design and structure. Once the tooth is isolated and kept dry, the layers of the tooth are incrementally replaced and instantly set with special lights, meaning that the entire filling can be built up and repaired by the time you leave the office.