This is a working police dog that recently fractured his left mandibular canine tooth. Since this fracture exposed the pulp chamber, it is called a complicated crown fracture. While this would be the cause of severe pain in people, and presumably is similarly painful in the dog, the signs exhibited by our canine patients are often rather subtle. This dog faced an early retirement if his fractured tooth was not fixed. He was scheduled for root canal therapy and placement of a metal crown. He also had excessive wear to the left maxillary canine tooth, and a crown was also recommended for this tooth to prevent further wear and/or fracture.
Notice that the fracture plane extends below the free gingival margin on the front (mesial) aspect of the right mandibular canine tooth. This, in addition to the relatively short remaining supragingival crown, necessitated a surgical procedure called crown lengthening. The goal of this procedure is create a larger surface area for cementation of the crown and to create a prepared margin that is at or below the fracture plane. This requires elevation of the attached gingiva, removal of bone around the tooth, then reattachment of the gingival in a lower position (more towards the root end). After the crown lengthening, the larger crown must be shaped and impressions made for laboratory fabrication of a full metal crown.
Additionally, this tooth must be treated with standard root canal therapy. This involves first removing the infected pulp tissue and shaping the canal with files so that it can be sterilized with 50% dilution of bleach (sodium hypochlorite). Then the canal is filled with a material called gutta percha, which along with a filling of the access cavity, creates a hermetic seal of the root canal.
The last step in the process is cementation of the full metal crown onto the prepared tooth.
Now this police dog is ready to go back to work!