B.A. Niemiec
Southern California Veterinary Dental Specialties, Dentistry, San Diego, CA, USA
Historically, restoration was a recommended therapy. However due to the progressive nature of the disease, this treatment carries a poor long-term prognosis and is no longer performed.
Teeth with radiographic but no clinical evidence of tooth resorption (TR) do not hurt in humans. Therefore, if a TR is seen on dental radiographs, a thorough evaluation of the cervical area of the tooth should be performed with an explorer. If no evidence of tooth resorption is found, extraction is not required. However, the owner should be informed and the teeth evaluated and radiographically monitored under general anaesthesia on a regular basis.
The current treatment of choice for clinical TRs is extraction. However, extractions can be very difficult in these cases due to tooth weakening and ankylosis (especially in type 2 lesions). Additionally, in some cases, there is little to no tooth structure remaining. In cases with significant weakening and/or ankylosis, performing the extractions via a surgical approach is recommended to speed the procedure and decrease the incidence of fractured and retained roots.
Determining type 1 from type 2 tooth resorption is critical for proper treatment of tooth resorption. Complete extraction is always the ideal treatment. However, crown amputation is an accepted treatment for advanced type 2 resorption.
There are 4 radiographic findings and one clinical that must be present for crown amputation to be performed.
1. No evidence of endodontic disease
2. No evidence of periodontal disease
3. No radiographically identifiable periodontal ligament
4. No radiographically identifiable endodontic system
5. No caudal stomatitis
Crown amputation is an acceptable treatment option for advanced type 2 lesions as it results in significantly less trauma and faster healing than complete extraction. This procedure, although widely accepted, is still controversial. Most veterinary dentists employ this technique, however in widely varying frequency. Veterinary dentists typically employ this treatment option only when there is significant or complete root replacement by bone. Unfortunately, the majority of general practitioners use this technique far too often. Those practitioners without dental radiology capability should not perform crown amputation. In these cases, the teeth should either be fully extracted or the patient referred to a facility with dental radiology.
Finally, root pulverization (atomization) is no longer considered appropriate for ankylosed teeth. If the tooth is ankylosed/resorbed to the point where even surgical extraction is impossible, crown amputation should be acceptable. In other words, if identifiable tooth structure is present, it should be removed; if not, crown amputation may be performed.
Crown Amputation Technique
After clinical and radiographic evaluation confirms that the tooth is a suitable candidate, crown amputation is initiated by creating a small gingival flap around the target tooth. A conservative envelope flap typically works well.
Next, a crosscut taper fissure bur on a high-speed handpiece is used to remove the entire crown to the level of the alveolar bone. The bone and remaining tooth should be smoothed with a coarse diamond bur.
Following clinical and radiographic confirmation that the tooth is removed to at least the level of the bone, the gingiva is sutured over the defect. Closure may require a small amount of fenestration to relieve tension.