Doctor Doctor – My Tooth Hurts

A cracked tooth, broken tooth, tooth hurts when biting, tooth sensitive but no cavity present are dental conditions that require immediate attention .

Cracked Tooth Molar
A cracked tooth may not always be visable.

One of the most common problems with teeth today is a cracked back tooth. Typically the further back in the mouth, the occurrence of a tooth problem increases. The uncomfortable tooth often is not broken.  Broken back teeth are often less painful than a cracked tooth before it breaks.

The signs and symptoms of a cracked tooth are:

  • Temperature sensitivity especially noticeable when pressure is placed on the tooth
  • The tooth location is far back in the mouth. The last molar is most likely and with each tooth forward the risk decreases some.
  • The problem tooth often shows signs of significant wear, indicating more than normal function against the tooth it bites against.
  • When checked with inked paper called articulating paper there are extensive areas of ink left on the tooth rather than a more normal point to point contact between the teeth.
  • Teeth with large dental fillings are weaker and therefore more susceptible to cracking and breaking.
  • The tips of the canine teeth (eye teeth) are worn off.

Why do teeth crack?

To understand this you must first understand what is normal. In a normal situation the upper and lower back teeth touch each other with point contacts. When a person chews the back teeth do not touch when the jaw moves from side to side. The four canine teeth (two upper and two lower) guide the jaws apart sending a signal to the brain to open the mouth when the jaw slides left or right. The back teeth only contact when the jaws are fully together. The at risk back teeth ideally only receive vertical force down the center of the tooth where they where designed to best receive heavy force.  Side forces on back teeth are not well tolerated and places the tooth at risk for developing a crack(s). If there is a filling in the tooth and especially if it is a large filling that is also a silver/mercury amalgam, the tooth crack risk is greatly increased. People who grind their teeth have increased risk of developing a cracked tooth..

What to do to prevent or treat cracked back teeth.

If the tips of the four canine teeth are worn down allowing the back teeth to contact heavily in side to side movements the individual should consider the value of placing dental restoration on the canines to improve jaw guidance by eliminating or lessening side to side forces on the back teeth.

If the individual grinds their teeth at night they should consider wearing a protective night guard over either the upper or lower teeth to lessen the stress on the teeth and the jaw muscles.

Tooth grinding and heavy tooth wearing can be an indication of tooth interference to normal jaw closure. The dentist may feel the individual could benefit from adjusting the bite.

If on routine examination the dentist notices a darkened crack line in a tooth, thought should be given to place a protective crown or onlay restoration to contain the walls of the tooth on either side of the crack preventing the crack from propagating through the tooth.

If left untreated the crack potentially could extend through the tooth to the nerve (pulp) area requiring root canal treatment. If the crack extends through the nerve area to the middle of the tooth where it meets the jaw bone, the tooth would need to be removed.

If the cracked portion ultimately breaks off the tooth, it frequently breaks down to where the tooth emerges from the bone requiring a surgical procedure called crown lengthening before the tooth can be restored with a crown.

For more information please see: Smiles by Design, the Lexington Dentist Smile Makeover Artist.

Dr. David Brother, DMD, FAGD Lexington Dentist ,  Smiles By Design 57 Bedford Street, Ste 110, Lexington, MA 02420