This fourth premolar demonstrates dark areas around each root tip.  This is a result of the tooth dying and the bone being destroyed around the root.  Once the pulp dies these changes occur over a period of months.  The patient is painful but most of the time does not show a distinct pain response to the handler or owner.  A root canal can be done to save a tooth even at this stage.  Allowing this to progress may result in further pain and compromise to other body systems.

This mandibular canine tooth has had a root canal procedure and a crown placed.  This radiograph was taken at the time of the crown placement and you can see the area around the root tip here is dark as well, indicating bone destruction.  This will heal as the source of the infection is removed with the root canal procedure.  The diseased pulp is replaced with gutta percha, which represents the white material within the root canal.

This is a patient following placement of four cast metal alloy crowns.  Crowns are placed to protect the integrity of root canal therapy and to protect the tooth from excessive wear like cage chewing and other trauma.  One last comment, the tooth does not have to be exposed by fracture for this to occur.  Dentin exposure due to wear or blunt trauma can also result in the same outcome.  Only x-rays can determine if this is occurring in these cases.

An unerupted, malformed tooth 304 is present and teeth 305, and 306 were radiographically missing with a retained tooth root in the region. Unerupted teeth may lead to dentigerous cyst formation with resulting regional bone loss.

An incision was made through the gingiva of the dorsal alveolar ridge with releasing incisions on both the buccal and lingual aspects of the mandible. The left mandibular third premolar was extracted to allow for better exposure (the left mandibular first and second premolars were previously extracted).

After creating a mucoperiosteal flap, bone was removed with a round carbide bur on a water-cooled high speed handpiece. After removal of the dorsal cortex, a piezoelectric surgery unit was used to expose the unerupted tooth and delineate the periodontal ligament space.

Dental elevators were used to gently elevate the tooth from the mandible. A root remnant of the previously extracted distal root of the mandibular second premolar was also identified and removed.

Due to the presence of significant amounts of cortical bone on the buccal, lingual and ventral surfaces of the mandible, no osteoconductive or osteoinductive substances were placed. The site was closed in two layers with 4-0 poliglecaprone 25 in a simple interrupted pattern.

Radiographically there are periapical lucency is seen surrounding both roots.  Root canal therapy or extraction are the options for this tooth.  Leaving it will allow the bone destruction to progress.  Pain is very likely a problem with these patients although almost none will be able to demonstrate it to the owner.