A cracked tooth is a tooth that has a fracture, split, crack or craze running somewhere through it. People are living longer and more stressful lives, and are exposing their teeth to many more years of crack-inducing habits, such as clenching, grinding and chewing on hard objects. These habits make our teeth more susceptible to cracks. In some cases, teeth that have been restored with silver (amalgam) fillings are at higher risk of cracking, as the metal filling can act as a wedge between the cusps, forcing them apart, creating fracture lines that can propagate downwards with daily function.
Cracked teeth show a variety of symptoms including erratic pain on chewing, pain with the release of biting pressure, or pain to extreme temperature. Cracks do not show up on x-ray and can occur at any age but are more predominate in the 30-50yr age group. Cracks can be visible in the tooth and diagnosed at your dental appointment, leading to planning options to treat and prevent the propagation of the crack. Cracks however, may also start in the root, way below the gum, making detection, diagnosis and treatment difficult.
Cracks that start in the crown of the tooth and propagate downwards may in time, extend into the nerve chamber, resulting in bacterial infection of the pulp and nerve death. At this point the options available are limited to extracting the tooth or performing a root canal treatment (see below). Restoration of a cracked tooth at this stage of involvement will involve a crown, but that is still no guarantee that the tooth may not crack further under the crown and result in eventual tooth loss.