ENDODONTIC TREATMENT IS UNKNOWN TERRITORY for most veterinary practitioners, but it is an area they should be exploring if they hope to maintain good welfare, along with the function and physical appearance of their patients’ teeth, clinicians attending VetsSouth were told.
Matthew Oxford, of the New Forest Veterinary Dental Service in Dorset, estimated that about one in three adults in the UK is likely to have undergone root canal surgery, but the number of pet animals that have received similar treatment is a tiny fraction of that figure.
A good reason for that would be that there are only about 10 practitioners in the country regularly carrying out this form of surgery in animal patients, but he argued that many more should be acquiring the skills and equipment necessary to offer the service.
There should be no shortage of patients as roughly 25% of dogs and 10% of cats have at least one fractured tooth. Any damage that exposes the dental pulp will allow the infiltration of bacteria from the mouth and in time this will overwhelm the animal’s immune defences, destroying the pulp tissue and leading to painful tooth root abscesses, he said.
Dr Oxford believed there were various reasons why endodontic treatment might be preferable to the current standard treatment of tooth extraction. One was the high likelihood of complications due to the physical force needed to remove teeth – for example, there was a significant risk of jaw fractures associated with the removal of mandibular canines, he said.
Keeping teeth in the pet’s mouth will not only maintain its cosmetic appearance but will also ensure that the animal is still able to process its food effectively and provide structural support for the surrounding tissues.
Tooth fractures in dogs are likely to occur when chewing on hard objects such as stones. Clients may not appreciate the risks of encouraging such behaviour by throwing them for the dog to catch. Later, they may also be unaware of the existence of a fractured tooth or the fact that it is likely to be painful, as most dogs will continue to eat normally.
Dr Oxford believed that looking for fractures should be a key part of any routine health check in veterinary practice. He reckoned that about one in 10 UK small animal clinics now have access to the specialised dental x-ray apparatus necessary to confirm the diagnosis of a tooth fracture and to assess the extent of the resulting damage.
Such lesions could be easy for a busy practitioner to ignore, but they should always be treated as “the longer you leave them the more pathology will develop and the less likely you will be to salvage something”. Moreover, tooth fractures in a young animal should be regarded as an emergency.
Neither the clinician nor the client can disregard the presence of a major bacterial infection within the dog’s mouth. He pointed out that the smell of necrotic tooth pulp is “pretty horrific”, a characteristic odour not dissimilar to that of a poorly maintained toilet.
It may be unwise for the dentist to attempt to maintain the viability of a newly fractured tooth as the failure rate in procedures on a live tooth is fairly high at around 25%. But the prospects are much better if the nerve supply is destroyed, the pulp removed and the root canal filled with biologically inert material. He suggested that 95% of the root canal procedures he has carried out have been successful, partly a result of the much simpler anatomy of the root structures seen in pet animals compared with humans.
Dr Oxford detailed the equipment, materials and processes involved in carrying out a root canal procedure in companion animal species. Returning to the earlier lavatorial theme, he pointed out that the removal of the live and/or necrotic pulp required a combination of brushwork and a liquid solvent of organic debris such as sodium hypochlorite (bleach).
Of course, the brush-like files used to remove the pulp are much smaller in diameter than equipment used in other situations and they have to be treated with care. During questions, he acknowledged that he has had a file break within the tooth canal of a patient on a couple of occasions.
Once, the file was near the tooth surface and “it was eventually removed after half-an-hour of sweating and swearing”.
On the other occasion, a small fragment had to be left inside the root, but that is perfectly acceptable if the area has been thoroughly irrigated to remove all the organic debris, he said.