Damage to the structure of the tooth.
The crown of the tooth is a complex structure comprising 3 separate components: enamel, dentine and pulp. Enamel forms the outer protective layer and is the hardest substance in the body. The underlying dentine is made up of tubules with nerve ending radiating outwards from the pulp. The pulp is a living, highly sensitive tissue containing blood vessels and nerves. Damage to any of these structures is of potential concern. Trauma to the tooth may result in wear, discolouration or a broken tooth. Wear (attrition) to the tooth occurs as a result of recurrent abrasion. This can be caused by tooth to tooth contact, inappropriate play or chewing activity, such as chewing the bars of a kennel, grinding on hard bones or continuous play with tennis balls. Pink, grey or purple teeth indicate that the pulp inside the tooth has bled, staining the dentine. Most of these teeth need treatment as the pulp has been irreversibly damaged. Fractured teeth result from sudden trauma to the tooth. The fracture may just involve the enamel, the enamel and dentine or all layers including the pulp. If the pulp is exposed the tooth will be extremely painful and need urgent treatment. Diagnosis Any change to the tooth needs to be assessed. A pink sheen at the fracture site or bleeding indicates the pulp is exposed. A black spot indicates the pulp is dying. Dental radiographs are necessary for all but the most superficial of enamel fractures. Under a general anaesthetic, a probe is used to assess whether the pulp cavity is exposed or not. ANY TOOTH WITH PULP EXPOSURE NEEDS URGENT ATTENTION and monitoring the tooth is NEVER appropriate. Treatment Fractures involving the dentine are sensitive and need treatment. If the pulp is exposed in worn or fractured teeth, the tooth either needs endodontic (root canal) treatment or extraction and should NEVER be ignored. Prevention To avoid fractures, do not throw stones for your dog and be careful about feeding bones. Wear can be avoided by using rubber balls instead of tennis balls for play. In dogs which are kennelled, metal crowns may be useful to prevent fracture or abnormal wear. Tennis balls are abrasive to teeth because the surface holds fine abrasive particles such as sand or soil when being played with.