This 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.
In general, for small to moderate sized fillings in front teeth and some small fillings in back teeth, composite resin is a good choice. Large fillings in front teeth may be temporarily filled with composite resin but generally require a crown.
In general, all back teeth are best filled with silver amalgam. Small fillings in back teeth could be filled with composite resin depending on the patient’s color preference and budget.
Large fillings or multiple smaller fillings made of silver amalgam or composite resin on the same tooth usually weaken the tooth and a crown should be used to strengthen the tooth. Large fillings could be made using gold or ceramic and may not need a crown.
Fillings that are on root surfaces, near or covered with gum generally need to be silver amalgam to obtain a lasting seal.
Unfortunately, composite resin is frequently used for moderate to large fillings in back teeth. Too often, there are problems with poor fit of the filling against the adjacent teeth resulting in food impaction and tooth movement. In addition, leakage between the filling and tooth causes sensitivity and decay. Also, difficulty making a proper biting surface results in subsequent wear and tooth movement. The movement of back teeth will result in the front teeth moving and becoming more crooked.