Cracked-Tooth Syndrome is identified more by symptoms than by actually seeing a crack in a tooth (x-rays do not show cracks in teeth). The primary symptom is pain on biting…sensitivity to cold is also often reported. The pain from biting occurs due to flexure of the crack when the tooth is put under a load, as in chewing.
In almost every instance, the cracked tooth has a sizable filling. A tooth with a large filling has been hollowed out – first by decay and then by replacing the decay with a filling. Over time the weakened remainder of the tooth builds up small fracture lines that become larger and deeper. In addition, a tooth becomes more brittle with age, leading to more fracture lines. A grinding or clenching habit also causes a massive increase in stress and strain on the teeth.
Success in treating a cracked tooth depends on the extent of the crack. Most cracks (90%) do not extend to the nerve of the tooth and are successfully treated with a crown. A crown acts like a belt to hold the tooth together. In those cases in which the crack extends to the nerve (9%), a root canal is often necessary to treat the injured nerve. In a few cases (1%), the crack may extend through the length of the tooth and extraction may be necessary.