A dental restoration or dental filling is a dental restorative material used to restore the function, integrity and morphology of missing tooth structure. The structural loss typically results from caries or external trauma. Aesthetic filling for back teeth is an alternative to silver (amalgam) fillings which are made of a strong composite resin that is matched to the surrounding tooth color. In the past, Aesthetic fillings were placed only on front teeth, but recently a stronger more durable material has been developed that can withstand the chewing pressure of back teeth. Dental restorations can be divided into two broad types: direct restorations and indirect restorations. All dental restorations can be further classified by their location and size.