Cracks and Fractures
One of the major problems of large silver amalgam fillings are cracks. Since the filling material is a metal and is subject to biting forces and hot and cold temperatures over time, expansion of the material occurs. Often times the filling material appears to be growing out of the tooth. When this occurs, lateral forces on
the walls of the
teeth are a result and this often leads to crack propagation underneath
the filling material. The resultant crack can propagate outward, which
usually leads to fracture of one of the walls of the tooth or it can
propagate toward the inner part of the tooth or pulp, which can lead to
a root canal.The cracks cannot be seen on an x-ray so often times we have to rely on clinical symptoms to diagnose them. Usually, there is a sharp, fleeting sensitivity to biting something hard and/or sensitivity to cold.
Prevention of cracks consists of converting large silver fillings to either a bonded restoration or some sort of onlay or crown before the cracks can propagate and cause more expensive damage.
