Should I be using amalgam or composite restorative materials?

Composite materials were first introduced for use in Class III and Class V cavities. They have now been accepted as the most popular material for the restoration of Class IV cavities and of fractured incisors and their use in Class I and Class II cavities has been advocated. Laboratory investigation of the physical properties of the composite materials suggests that with the exception of hardness, the values recorded are comparable with those for amalgam. In their favour are a lower coefficient of thermal conductivity and superior aesthetics. It has been claimed that a Class II composite restoration can be placed more easily and more rapidly than an amalgam but if comparable contour and adaptation is to be achieved, this claim cannot be substantiated. In contrast to laboratory studies, clinical research has shown that composite materials have some shortcomings. Their colour tends to become more yellow with time and their ability to resist marginal percolation is inferior to that of amalgam. Under clinical conditions their resistance to abrasion is unsatisfactory because of the failure of the bond between the filler particles and the resin. On balance, at the present time amalgam is preferable to composites for Class I and Class II restorations except in cases where aesthetics is the overriding consideration.