Cracked Tooth Syndrome (CTS)

Cracked Tooth Syndrome (CTS)


CTS Defined

When teeth have been heavily filled, it is not unusual that they develop a cracked (or split) tooth syndrome (CTS). Symptoms include a sharp pain when you bite down into something hard. When you open your mouth and the teeth are no longer touching, the pain goes away.

The most common sites of occurrence of CTS are the premolars and molars, back teeth that grind and crush food. Often the tooth has an extensive filling (usually silver amalgam) that has been in place for a long time. Occasionally, CTS occurs in a tooth that has recently been drilled and a great amount of tooth structure has been lost. However, split-tooth syndrome can also occur in teeth that only have a small silver filling. In most instances, the filling has weakened the tooth just enough so that when you chew or bite, the tooth and filling separate slightly (flex), causing immediate and sometimes severe pain. The pain does not usually linger after the biting action is finished.

The fact that you feel pain when pressure is applied to the tooth means that the nerve is being affected. If the problem is not solved quickly, the nerve may die and the tooth will then require endodontic treatment (root canal).


Treatment will involve at least one x-ray to assist in the diagnosis to help rule out other causes. We will try to find the section of the tooth that is causing the problem by pushing on the various sections of the tooth or having you bite on a hard object. When the section of the tooth that is cracked is found, it makes treatment easier. First, the tooth is anesthetized and the old filling is removed. Then we carefully inspect the area to determine whether the cracked section can be seen. Very often it is visible at this point. The next step is to see whether the split area can be fixed with a direct filling (bonded). This is the ideal situation if the crack is small. Unfortunately, this rarely occurs. More often (over 95% of the time), the biting surfaces of the tooth must be entirely covered and protected first with a provisional (temporary) onlay or crown. 

If this is successful in eliminating the pain (we usually wait for a few weeks to be sure the problem is resolved), an impression for a laboratory-fabricated casting¾either a porcelain or resin onlay or a crown¾is made. If adequate tooth structure remains, a partial coverage restoration¾an onlay¾is preferred.  If the tooth has been badly cracked or if not much tooth remains, then a crown will be necessary. The purpose of either type of cast restoration is to unite all sections of the tooth so it cannot move or separate under normal biting forces. If the provisional restoration is successful in eliminating the pain, we expect that the final cast crown or onlay will correct the problem.

Delaying Treatment

What happens if CTS is not treated quickly? The best you can hope for is that the tooth continues to hurt only when you chew or bite. This does not often happen. Usually, the broken section of tooth gets weaker and weaker until it fractures off. Additionally, if the crack gets deeper into the tooth, the nerve will die and the tooth will need endodontic treatment before the crown or onlay is placed. Sometimes the nerve is immediately affected by the initial split and dies. This may occur quickly or may take years before it is evident. Every case of CTS is unique.

If it is any consolation, the cracked tooth is not your fault. It is a result of your teeth being drilled and filled with big silver fillings when you were younger. We see this particular dental problem mostly in patients who are between 25 and 45 years old.

Unfortunately, cracked teeth do not go away. Many times, they only hurt when you bite on them from one particular angle. If the fractured segment is not stressed, the tooth feels normal. You might also be able to “train” yourself to chew on different teeth and avoid the cracked tooth. At best, you only postpone necessary treatment while the nerve may be slowly dying.

If you have any questions about cracked tooth syndrome, please feel free to ask us