A common finding during an oral examination of a dog or cat patient is the presence of a fractured tooth (or teeth). Some veterinarians may advise owners to just “watch” the tooth, and if it becomes painful, return so that the tooth can be extracted. Other veterinarians advise that a fractured tooth should always be extracted, since that is the only remedy that general practitioners can perform. However, times are changing, and more veterinarians and owners realize that teeth are important for pets, and that not every fractured tooth needs to be extracted. There is a better way to manage such injuries by referring the patient to a board-certified veterinary dentist®. If given the choice between extraction of a fractured tooth or repair of the tooth, most owners would elect the latter option. If an alternative to extraction is not offered, owners may resent not being told about an alternative treatment. At Animal Dental Specialists of Upstate New York, we have the knowledge, equipment, and expertise to save fractured teeth (unless they are hopelessly damaged) without resorting to dental extraction.

The teeth of humans, dogs, and cats are hollow inside and contain sensitive nerve and vascular tissue referred to as the pulp (Figure 1 A). At the tip of the root (apex), numerous small channels allow sensory nerves and blood vessels (red arrows) to enter and exit the tooth. When the crown of a tooth is fractured, the pulp tissue becomes exposed to hundreds of different species of bacteria and other microorganisms that naturally are present in the oral cavity (Figure 1 B). Over time, the pulp tissue inside the tooth dies, and the microorganisms begin to ooze out through the tiny channels in the root apex (green arrow), resulting in microbial contamination of the surrounding jawbone (Figure 1 A).

Figure 1. 

A.

B.

We can recognize microbial contamination of the bone on X-ray or CT imaging. Healthy bone appears white, but infected bone is softer, demineralized and appears less dense (not as white),  appearing like a dark halo around the root apex (Figure 2 A). Treatment involves complete removal of the contaminated pulp, chemical sterilization of the interior of the tooth, and then filling the center of the tooth (pulp cavity) with inert filling material.  A composite restoration is applied over the fracture site in the crown. This procedure to repair a fractured tooth is referred to as “root canal” treatment.  Once the pulp cavity is cleaned and chemically sterilized, it is no longer possible for microorganisms to seep out of the root apex into the surrounding bone, so the body’s immune cells can clean up the bone infection. Successful treatment is confirmed on follow-up imaging (Figure 2 B), in which normal bone is filling-in the once dark area around the root apex.

If extraction of the above tooth (the right upper canine tooth, 104) had been elected as treatment for the crown fracture, an incision in the gum tissue would have been necessary to reflect the soft tissue away from the bone. Some of the bone would need to be removed, in order to create room for instruments (dental elevators) to be placed between the root and the bone, to begin to loosen the tooth. Once the tooth has been elevated and extracted, the socket is cleaned and irrigated, and sharp edges of bone would be smoothed. The gum tissue would then be sutured over the extraction site with fine, absorbable sutures. Oral restrictions to prevent damage to the sutures would need to be enforced for ten days. By contrast, with root canal treatment, there is no incision, no bone removal, no sutures, and oral restrictions are minimal. If your pet unfortunately sustains a tooth fracture, explore all options for treatment.

Not every tooth is amenable to root canal therapy. Teeth that are severely fractured or which have extensive bone damage around the root apex are best managed by extraction. Also, some teeth are more important than others, so we generally consider root canal treatment if one of the eight “strategic” teeth are fractured and can be salvaged. The eight strategic teeth are the four canine teeth and the four largest gnawing teeth in the back (upper fourth premolar tooth and lower first molar tooth). In cats, root canal therapy is generally restricted to damage to the canine teeth.