Tooth fracture: Should you ever just "wait and see?" (Proceedings)

Tooth fracture may affect the crown and/or the root. In most cases tooth fractures are painful to the patient. It is imperative that patients with tooth fractures have a diagnostic workup to assess the stage of the fracture and what treatment options are available.

Patients with pain from a tooth fracture can show these clinical signs: chewing on one side, dropping food, excessive drooling, tooth grinding, pawing at the face, facial swelling, regional lymphadenitis, head shy behavior, refusing hard food, treats or toys, aggressive behavior.

Crown fractures

There are two classifications of crown fracture-complicated and uncomplicated. Complicated fractures means the fracture line exposes the pulp and uncomplicated fractures do not have exposure of the pulp. Diagnosis of the fracture classification is done with the patient under anesthesia using a dental explorer to examine whether the pulp has been exposed.

Complicated fractures

When the pulp chamber is exposed, the pulp becomes inflamed and can spread into the root. Pulpitis and pulpal death can occur if no treatment is provided. Pulp exposure is painful to the patient. If treatment is not going to happen right away, antibiotics and pain medications should be dispensed.

If a complicated fracture occurs to a deciduous tooth, the deciduous tooth should immediately be extracted so as to not cause damage to the permanent tooth bud.

If a complicated fracture occurs to a permanent tooth, the treatment options are extraction or root canal therapy. If the fracture goes below the cementoenamel junction or the root is diseased, root canal therapy has a higher incidence of failure and extraction must be performed.

Immature permanent teeth are found in those patients up to 18 months old. The pulp chamber in these patients makes up the bulk of the tooth and as the patient ages, more dentin is laid down and the pulp chamber narrows and the root apex closes. It makes sense that these teeth should be allowed to finish the development of the root apex. Vital pulpotomy therapy is an endodontic procedure that can be done if the fracture is less than 48 hours old. The unhealthy portion of the pulp is removed and a material is placed to irritate the pulp and cause it to make a dentinal bridge to seal off the healthy pulp. A tooth colored restoration is then placed on top. These patients must be monitored radiographically at 6 and 12 months post operatively to check the stabilization of the tooth. If the therapy fails, root canal therapy or extraction must be performed.

Uncomplicated fractures

Teeth with uncomplicated fractures have exposure of the dentinal layer. The dentin is made up of microtubules that allow communication between the pulp and the oral environment. Exposure of the dentin can result in pulpitis or even pulpal death if left untreated. Minimally, the tooth is sensitive and may cause some pain to the patient.

Treatment usually involves sealing the dentin to stop any sensitivity. This can be done using a bonding agent or a restorative material if the defect is slightly larger. The treated tooth must be monitored with oral examinations and dental radiographs to make sure the pulp remains vital. If the pulp does not remain vital then extraction or root canal therapy must be recommended.

Crown and root fractures

Crown and root fractures can be classified as complicated or uncomplicated depending on whether the fracture line crosses into the pulp. Diagnosis is attained by examination using a dental explorer and dental radiography. If the fracture line does not involve the pulp and does not extend 4-5mm beyond the cementoenamel junction, restoration can be performed. If the pulp is exposed, root canal therapy needs to be performed prior to restoration. If the fracture goes beyond 5mm, the tooth needs to be extracted.

Root fractures

Chewing on flexible objects most times causes root fractures. Root fractures are usually diagnosed radiographically. The most obvious clinical sign is a mobile crown. The more mobile the crown is the higher on the root is the fracture. Fractures are horizontal or oblique. Horizontal fractures have the best prognosis if they are near the root apex. Long axis fractures have a poor prognosis and should be extracted. If the root fracture is stable and the pulp is vital and not contaminated, acrylic splints can be used for stabilization. Root fractures can heal by a dentino-cemental callus, connective tissue formation, fibrous union or osteofibrous union.

AVDC dental fracture classification

     • Enamel Infarction (EI): An incomplete fracture (crack) of the enamel without the loss of substance.

     • Enamel Fracture (EF): A fracture with loss of crown substance confined to the enamel.

     • Uncomplicated Crown Fracture (UCF): A fracture of the crown that does not expose the pulp.

     • Complicated Crown Fracture (CCF): A fracture of the crown that exposes the pulp.

     • Uncomplicated Crown-Root Fracture (UCRF): A fracture of the crown and root that does not expose the pulp.

     • Complicated Crown-Root Fracture (CCRF): A fracture of the crown and root that exposes the pulp.

     • Root Fracture (RF): A fracture involving the root.

Discolored teeth

Discolored teeth or intrinsic staining is a tooth discoloration that begins within the tooth. Discolored teeth are caused by blunt force trauma. The pulp of the tooth begins to bleed through the dentinal tubules where it becomes visually apparent on examination. The tooth starts with a pink color and as the blood degenerates, the color changes to a blue-gray and then a brown gray. If the damage is not too severe, the pulp does have the ability to heal. Teeth with darker discoloration have suffered an irreversible pulpitis. In an in-clinic study of teeth that were discolored, 92.2% of the teeth studied had gross signs of partial or total pulp necrosis. With this information it is safe to assume that all discolored teeth need to have either endodontic or exodontic therapy.

Worn teeth

Teeth in the dog and cat are worn in two ways: dental abrasion and dental attrition. Dental abrasion is when the wear comes from an outside source such as pruritis, an abrasive toy covering, cage chewing or aggressive chewing behavior. Dental attrition is tooth-to-tooth wear which occurs from normal use and from malocclusion. The teeth will form a brown spot on the occlusal surface. This is where the dentin is exposed and the tooth will protect itself by laying down tertiary dentin. Worn teeth need to be examined on a regular basis to assess if the wear has caused a true pulp exposure. In some cases, placement of a crown can prevent further damage that could potentially expose the pulp. If a pulp exposure does occur, root canal therapy or extraction is recommended treatment options.

Bibliography

Bellows J. Endodontic equipment, materials and techniques. In: Small Animal Dental Equipment, Materials and Techniques. Ames, Blackwell, 2004, 175-229.

Dupont G. Pathologies of the dental hard tissues. In: Niemic BA. Small Animal Dental, Oral and Maxillofacial Disease. London, Manson, 2010, 127-157.

Gorrel C. Emergencies. In: Veterinary Dentistry for the General Practitioner. Edinburgh, Saunders, 2004, 131-155.

Holmstrom SE, Frost Fitch P, Eisner ER. Endodontics. In: Veterinary Dental Techniques for the Small Animal Practitioner, 3rd ed. Philadelphia, Saunders, 2004, 339-414.

http://www.avdc.org/nomenclature.html#resorption

Hale FA. Localized intrinsic staining of teeth due to pulpitis and pulp necrosis in dogs. J Vet Dent, 2001 18(1): 14-20.