The Complete Oral Health Assessment and Treatment (Dental COHAT)
World Small Animal Veterinary Association Congress Proceedings, 2019

K. Istace, RVT

Mayfield Animal Hospital, Edmonton, AB, Canada

The complete oral health assessment and treatment (Dental COHAT) comprises of 10 steps.

Chlorhexidine Rinse

A solution of chlorhexidine gluconate 0.1% is applied to the surfaces of the teeth. This solution kills surface bacteria on the teeth and gingiva, reducing the number of bacteria aerosolized during cleaning.

Supragingival Scaling

Removal of plaque and calculus from tooth crowns. This can be done manually, with calculus removal forceps and hand scalers, or with dental cleaning machines such as ultrasonic scalers.

Calculus removal forceps are used to remove heavy calculus deposits from teeth by placing the hooked blade at the top of a calculus deposit (being careful not to damage the gingiva!) and the other blade on the lingual surface of the tooth. The forceps are gently squeezed (being careful not to damage the tooth surface!) and pulled or rolled coronally to dislodge a large chunk of tartar. This instrument speeds up the cleaning process, decreases wear and tear on more delicate hand instruments and ultrasonic instruments tips, and decreases aerosolization of bacteria.

Hand scalers are used supragingivally only as their pointed tip and sharp back will damage soft tissues. They are used in a push or pull stroke away from the gingiva to remove tartar. Curettes may also be used in this way on the crowns of teeth.

Ultrasonic scalers vibrate at high frequencies which generate significant heat therefore a steady stream of water is used to cool the tip. The side of the tip (not the end!) is placed in contact with the tooth, and calculus is removed by mechanical kick (metal tip vibrating against calculus) and cavitation (energized water spray). The tip should not be held in contact with the tooth for more than 10 seconds at a time to prevent thermal damage and tooth death. If you cannot complete cleaning a tooth within that time, move onto the next tooth and come back to the first one later.

Once all of the teeth surfaces have been cleaned, ensure that all plaque has been removed. Plaque is often not apparent to the naked eye. Two methods can be used to detect missed plaque: 1) Drying the teeth with an air/water syringe. Any missed plaque will be visible as a chalky substance. 2) A commercial plaque-revealing product. These brightly stained liquids are painted onto the teeth, then the mouth is rinsed with water. Any stain remaining on the teeth is an area of missed plaque. These liquids can also stain the patient’s fur, so care must be used when applying and rinsing them.

Subgingival Scaling

Removal of plaque and calculus from the gingival sulcus. Curettes or most ultrasonic scalers can be used for this. A curette is gently introduced into the sulcus, then angled to bring the blade into contact with the tooth or root surface (root planing), and a pull stroke (either vertical, horizontal, or oblique) is used to dislodge calculus and debris and remove it. Continue until the surface of the tooth feels smooth—this can be verified with a dental explorer: if there are no rough areas, the subgingival portion of the tooth is clean. Subgingival curettage may be performed to clean the tissue of the sulcus in periodontal pockets: the curette is introduced gently into the sulcus, then is angled to bring the blade into contact with soft tissue. Another finger applies light pressure on the outside surface of the gingiva, and the curette is used with a pull stroke to debride any diseased or necrotic tissue, bacteria, or debris.

Oral Examination and Charting

Evaluate the head, face, the oral cavity including throat and tongue, and the gingiva for any abnormalities including malocclusion, stomatitis, lacerations, granulomas, foreign bodies, etc. Then, beginning in quadrant 1 (upper right) and continuing through each quadrant, evaluate each tooth and record any pathology on the patient’s dental chart.


Use a fine polishing paste (medium and coarse pastes are not advised as these remove too much tooth enamel) in a polishing cup on a prophy angle attached to a low speed handpiece to smooth tooth surfaces. A light hand should be used during polishing to decrease heat production from the polishing cup. Keep the speed of the handpiece even throughout polishing by maintaining steady pressure on the pedal. Most compressors and electric motors have a speed gauge. The handpiece speed should not exceed 3000 rpm.


Flush tooth surfaces and pockets to remove all loose debris and polishing paste. Any material left behind can cause inflammation or abscesses of the gingiva. There are several different methods of irrigating teeth and periodontal pockets: 1) an air/water syringe, 2) a blunt-tipped needle or urinary catheter on a large syringe filled with water, saline, or chlorhexidine rinse, 3) an abscess-flushing syringe filled with water, saline, or chlorhexidine rinse.


Often, radiography will reveal more pathologies such as bone loss, tooth resorption, tooth root fracture, tooth impaction, dentigerous cysts, internal root resorption, retained root tips, etc.

Additional Procedures (As Required)

For veterinary technologists, this usually comprises of closed root planing and perioceutic application. Root planing is performed when normal gingival attachment has been lost and the tooth roots must be cleaned of calculus and debris. Closed root planing comprises of thorough subgingival scaling and curettage. Its aim is to remove all debris and necrotic tissue, and to create a smooth root surface so that gingival attachment may occur.

Closed root planing may be performed on teeth with pockets of 6 mm or less. Open root planing, which may be performed to salvage teeth with periodontal pockets greater than 6 mm, requires the creation of a gingival flap and is considered a surgical procedure that must be performed by a veterinarian.

Perioceutics are instilled into cleaned periodontal pockets to aid in gingival reattachment. Perioceutics typically consist of a biodegradable gel, which acts as a carrier for antibiotics such as doxycycline. The gel is usually kept refrigerated and must be mixed before use. Follow the manufacturer’s instructions for storing and mixing. The gel is injected into the bottom of a root-planed periodontal pocket using a blunt-tipped needle. Once solidified (a few drops of cold water can be used to speed up this process), the gel is packed down into the pocket with a plastic or metal packing instrument (a curette or periodontal probe may also be used for this). The gel will release antibiotics into the pocket at much higher levels than systemic antibiotics, and dissolves within two weeks.

Any other required procedures such as extractions, biopsies, endodontic treatment, etc. are now performed by the veterinarian, and recorded on the dental chart by the technologist.

Fluoride Application (Optional)

In humans, fluoride has been proven to kill oral bacteria, help prevent tooth sensitivity, and strengthen teeth by encouraging enamel remineralization. This has not been proven in animals, though many veterinarians choose to use it due to the similarities of tooth structure and composition across different species. Several different types of fluoride are available, including acidulated phosphate fluoride and sodium fluoride. Fluoride solutions come in foams, liquids, or gels. These are applied directly to the animal’s teeth (make sure the teeth are dry to ensure maximum effectiveness) using a gloved finger or gauze, left on for the required amount of time (usually 1–3 minutes, see label directions), then are thoroughly wiped off so that none remains to be swallowed by the patient.

Regardless of what type is used, remember that fluoride is toxic, even in small doses! Do not rinse with water, as this will interfere with the fluoride’s action.


Suctioning of the oral cavity and/or removing of any packing material such as gauze from the throat.

Note: The above steps may be altered somewhat in their order depending upon personal preference or situation (i.e., radiographs may be performed first if a client or veterinarian wishes to know exactly what dental work needs to be done on the patient). As long as all steps are completed thoroughly and in an order that makes sense (i.e., polishing must always be followed by irrigation to remove polishing paste from the gingival sulci) the patient will reap the benefits of a dental COHAT.


Speaker Information
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K. Istace, RVT
Mayfield Animal Hospital
Edmonton, AB, Canada