A tooth could be broken due to two main causes, weaken tooth structure due to severe caries/tooth decay or as a result or trauma.
A severely carious/decayed tooth or a tooth with large restoration/filling loses its supporting tooth structure gives way easily under increased biting force.
Tooth chips off under biting force due to
weakened tooth under a large filling
The front teeth especially the incisal teeth are most susceptible to fracture due to trauma when a person :
- falls face down
- knocked on the face by hard objects or
- knocked on the face during close contacts.
The incisal edge chips off due to a fall
or a knock on the tooth
A person with protruding front teeth has a higher risk of fracture during a trauma.
A tooth that has a necrotic/dead pulp tissue as a result of caries/tooth decay or trauma is also prone to fracture as it has lost the vitality.
Severely caries/decay tooth can easily break on biting
In some instances, a tooth may present with fine crack which is not visible with naked eye. The diagnosis will depend on the symptoms/complaints of the patient, careful clinical examination and inspection.
Cracked Tooth Syndrome (CTS)
Cracked tooth syndrome (CTS) refers to an incomplete fracture of a living/vital tooth usually involving the back/posterior teeth. The crack involves the dentine i.e the second layer of tooth and may extend to pulp, where nerves and blood vessels are.
It is rather difficult to diagnosis CTS as patient cannot pin point the exact tooth or quadrant that gives the discomfort or pain. To come to the right diagnosis, the dentist has to obtain a careful history of the symptoms bearing in mind CTS as a provisional diagnosis. Most often patient complaints of an uncomfortable sensation or pain from a tooth during chewing hard foods and which ceases when the pressure is removed. The patient may also present a history of numerous dental procedures with no satisfactory results to resolve the problem.
The dentist can use several aids to perform “bite tests” where the patient is instructed to bite on various items such as a toothpick, cotton roll, wooden stick,or a commercially available Tooth Slooth(an instrument specifically designed to aid in the diagnosis of fractures).
|The dentist may ask the patient to bite on a tooth slooth to determine where the crack is.|
Repairing Broken Tooth
1. Fine crack with tooth structure intact
Usually patient experiences on and off pain during food intake after the minor crack. If there is no continuous pain, no treatment is required. However, the patient has to follow up regularly by a dentist so that treatment can be instituted once the cracks become bigger.
2. Chipped tooth/tooth fracture involving only the enamel.
This occurs commonly if the person is not careful when biting on hard food or has the bad habit of using the front teeth to bite off strings or open bottle cap. If the tooth fracture involves only the enamel, the patient usually has no complain of pain taking food or drink.
The chipped tooth can easily be restored by bonding using a composite material/tooth colored filling material with minimal tooth cutting/tooth preparation.
Patient must be careful not to bite hard on the tooth to avoid the filling chipping off under force.
3. Tooth fracture involving the dentine layer
Dentine is the second layer covering a tooth. As dentine consist of tubules which when exposed causes sensitivity to thermal changes and air, it has to be restored. The broken tooth can be restored by bonding using composite/tooth colored material. Tooth preparation has to be done for good bonding. One has to avoid hard food as the filling may crack under high biting pressure.
4. Tooth fracture involving the pulp
If the fracture cuts through dentine layer and reaches the pulp tissue, there will be sharp pain and pulpitis occurs. Pulpitis is inflammation of the pulp tissue as a reaction to trauma.
If it is only a pin point exposure, a direct pulp capping can be done i.e. applying a dental material consisting of calcium hydroxide. Calcium hydroxide reduces the inflammation and promotes pulp healing. The fracture is then temporary restored. The temporary dressing is left for a few months. When there is no pain or signs of pulpal damage, the tooth can be restored in the same way as fracture involving the dentine layer. Discoloration of tooth and presence of an abscess or fistula on the mucosa are signs of pulpal damage or infection.
If pain persists, partially or complete removal of the pulp tissue, a procedure called root canal therapy has to be done.
If the pulp exposure is more than a pin point, root canal therapy will have to be done.
After the root canal is completed and there are signs of healing, the tooth can be restored by simple composite or by a crown if more than 2 thirds of the crown are fractured.
If it is a severely carious tooth which is already non-vital/dead, root canal therapy is done first to remove the necrotic/dead pulp tissue before the tooth is restored by a crown.
5. Fracture tooth that involves the root
If the fracture extends into the root of the tooth or involves the root, extraction may be the best option.