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DIAGNOSIS & TREATMENT OF CROWN FRACTURES | COMPLICATED CROWN FRACTURES A complicated crown fracture is a fractured tooth with direct pulp exposure (Figures 3 and 4).1,2 It has been reported that 10% of dogs have teeth with pulp exposure.3 Prior to tooth necrosis, the viable nerve can be very painful. Over time, the constant bacterial attack from the oral cavity results in tooth death. Once a tooth becomes nonvital, the root canal system acts as a bacterial super- highway, leading to local infections as well as bacteremias, which have been linked to serious systemic disease.4 Pet owners are often reluctant to pursue therapy for frac- Figure 1. Uncomplicated crown fracture of the maxil- lary left fourth premolar (208) in a dog. The dark area at the cusp is the stained, exposed dentin; note how thin the bright white layer of enamel is. Most owners see a noticeable improvement in their pets’ attitudes and energy levels after therapy is provided. tured teeth because they think “it does not seem to bother the dog.” However, fractured and/or infected teeth do affect animals by creating pain, infection, and fatigue; but these signs are often subtle or hidden. Pet owners should be educated that animal patients are typically much more stoic than their human counterparts when dealing with pain.5 Figure 2. Uncomplicated crown fracture of the mandibular left canine (304) in a dog. This is a fresh fracture as the dentin is not yet stained. Even though the fracture is significant, the pulp is not exposed. Both types require therapy, but treatment differs depending on the physical and radiographic appearance. The most commonly affected teeth are the canines and carnassials (maxillary fourth premolars and mandibular first molars). UNCOMPLICATED CROWN FRACTURES Uncomplicated crown fractures are very common in large-breed dogs, affecting approximately 60% of these patients in my experience. These types of fractures occur when a piece of crown is broken off, exposing the dentin but not the pulp (Figures 1 and 2).1 Figure 3. Complicated crown fracture of the maxil- lary right fourth premolar (108) in a dog. Note the pink spot in the cusp tip, which is the exposed root canal; this can be a painful condition. This can be a very painful condition, but veterinary patients rarely show clinical signs. Consequently, these tooth fractures are only diagnosed by careful oral examination, often under general anesthesia. Figure 4. Complicated crown fracture of the maxillary right canine (104) in a dog; infection is also present in this patient. July/August 2011 Today’s Veterinary Practice 19