"COHAT "represents a complete oral health assessment and treatment. This approach is superior to teeth cleaning procedures alone because the focus is directed at both plaque bacteria removal and control. Additionally, the COHAT strategy emphasizes diagnosis and specific treatment(s) to control periodontal disease and for specific patients, to reverse the destruction caused by the disease process. The companion animal owner is key in the COHAT strategy to help monitor and control periodontal disease.
Comprehensive oral health assessments start in the exam room with the physical and oral exams. Diagnostic procedures included in the COHAT procedure are dental radiographs and periodontal probing with charting of those findings.
Supragingival and subgingival scaling including: periodontal probing, oral evaluation, and dental charting.
The oral exam is a critical and meticulously performed. The entire oral cavity must be systematically evaluated using both visual and tactile evaluations. Please refer to the oral exam article authored by Dr. Kressin and published in Compendium of Continuing education for Veterinarians.
Careful visual examination is performed during the periodontal evaluation. The periodontal probe should be inserted at four points around EVERY tooth to identify periodontal pockets. This is performed by gently inserting the probe into the pocket until it stops and then "walking" the instrument around the tooth. The normal sulcal depth in a dog is 0-3 mm, and a cat is 0-1.0 mm. All abnormal findings are recorded on the dental chart.
Dental charting is used to record all problems. These charts are helpful when comparing the pet's oral health from visit to visit.
Dental radiographs are of tremendous value for veterinary patients. Full mouth dental radiographs are preferred to establish baseline documentation of the oral and dental anatomy. Case by case decisions need to be made on whether full mouth radiographs are indicated for patients being re-evaluated. Dental radiographs should be performed of ALL pathology noted on dental exam. This includes any periodontal pocket which is larger than normal, fractured or chipped teeth, masses, swellings, or missing teeth. Dental radiographs are a critical aid in the evaluation of dental pathology.
COHAT is great for the recognition of problems and for treating them. It is ideal to have a telephone contact number to discuss all abnormal findings. COHAT includes all available information (visual, tactile, and radiographic), and only then decisions on appropriate therapy are made with the pet owner.
Any pockets greater than normal for the species are pathologic and in need of therapy. Periodontal therapy is aimed at removing the infection from the root surface (plaque, calculus, granulation tissue and foreign objects), as well as, smoothing the diseased root surface. This will allow for reattachment and decrease in pocket depth.
In the canine patient, pockets between 3 and 5 mm which do not have mobility, or other issues, are best treated with closed root planing and subgingival curettage. This step is performed in a similar manner to subgingival scaling above, with a combination of mechanical and hand scaling. This is meticulously performed in order to achieve as clean a tooth as possible to promote healing.
Pockets greater than 5-mm or with furcation level 2 or 3 exposure require direct visualization of the root surface for effective cleaning. If the tooth is not effectively cleaned, the infectious agents remain along with the plaque and calculus. Visualization is best accomplished via periodontal flap procedures. These procedures are very effective in animal patients. If the clients are interested in salvaging the teeth, periodontal surgery can be performed. If advanced procedures are planned, it is essential that daily teeth brushing can be performed at home!
Mechanical subgingival scaling:
Mechanical ultrasonic scalars decrease anesthetic time. These scalers vibrate at approximately 45,000 Hertz and are highly effective in removing plaque bacteria and debris.
The area of maximum vibration is 1-3 mm from the tip. Do not use the tip or back of the any instrument (other than a magnetostrictive) as these are not effective for calculus removal, and can potentially damage the tooth. The instrument is placed on the tooth and LEFT on the tooth for up to 15 seconds. Once the instrument loses contact with the tooth, the scaler can no longer be effective. Run the instrument SLOWLY over the tooth surface and pocket in wide sweeping motions to cover every mm2 of every tooth surface. The use of mechanical scalers is relatively easy and allows for the removal of the vast majority of calculus. Therefore, this is performed first, and hand scaling used as a final check of cleaning quality.
Subgingival hand scaling (Root planing and subgingival curettage) is performed with curettes. A curette has 2 cutting edges, and a blunted toe and bottom. In this way, it will not cut through the delicate periodontal attachment as long as excess force is not applied. Cleanliness can be further evaluated by gently directing compressed air into the sulcus. Any remaining calculus will appear chalky against the root surfaces.
Polishing: Scaling (especially mechanical) leaves the tooth surface (and especially the root) rough, which increase plaque attachment. Polishing will smooth the surface of the teeth which will retard plaque attachment. Polishing is performed with a prophy cup on a slow-speed hand-piece with a 90 degree angle.
Sulcal lavage: The cleaning and polishing steps will result in debris such as: calculus and prophy paste (some of which is bacteria laden) to accumulate in the gingival sulcus. In some cases there are visible deposits, but in all cases, there is microscopic debris. These substances will allow for continued infection and inflammation. Therefore a gentle lavage of the sulcus is performed.