Brook A. Niemiec, DVM, DAVDC, FAVD
The basis of periodontal therapy today is plaque control. This is accomplished via two to four components depending on the stage of the disease. These include a thorough dental prophylaxis, periodontal surgery, homecare, and extraction. The cornerstone of periodontal therapy is a thorough dental prophylaxis. This must be performed under general anaesthesia, including a properly inflated endotracheal tube. The prophylaxis should include the following steps:
Step 1: Presurgical Exam and Consultation
This is often a much neglected step of a professional dental prophylaxis. The veterinarian should perform a complete as possible physical and oral exam. The physical exam will help ensure anesthetic safety. The oral examination will identify obvious pathology, as well as allow for a preliminary assessment of periodontal status. The veterinarian can then discuss the various disease processes found and the various available treatment options. Based on the physical findings, the practitioner can create a more accurate estimate, both financial and time, both of which will decrease problems with overscheduling and client finances.
Step 2: Chlorhexidine Lavage
The oral cavity is a contaminated area and a dental cleaning is a mildly invasive procedure. In this way, it often results in a transient bacteremia. For this reason, it is recommended to rinse the mouth with a 0.12% solution of chlorhexidine gluconate to decrease the bacterial load.
Step 3: Supragingival Cleaning
This can be performed via mechanical or hand scaling. The mechanical scalars decrease anaesthetic time and include both sonic and ultrasonic types. The most common type of mechanical scaler in veterinary dentistry today is the ultrasonic scaler. There are two main types: magnetorestrictive and piezoelectric. Both of these scalers vibrate at approximately 45,000 Hertz. They are very efficient and have an additional benefit of creating an antibacterial effect in the coolant spray. They can, however, be more damaging to the tooth, and may leave some calculus behind. Thus, it has been recommended that hand scaling be performed after ultrasonic scaling to ensure the complete removal of calculus. Sonic scalers run on compressed air and vibrate at 8-18,000 hertz. The area of maximum vibration is 1-3 mm from the tip. Do not use the tip or back of the instrument 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 in wide sweeping motions to cover every mm2 of every tooth surface.
Hand scaling is performed with a scaler. This is a triangular instrument with sharp cutting edges. In addition, the tip is very sharp. Scalers are designed for supra-gingival use only. The scalers (as well as curettes below) are held with a modified pencil grip. The instrument is gently held at the gnarled or rubberized end with the thumb and index finger tips. The middle finger is placed near the terminal end of the shaft and is used to feel for vibrations, which signal residual calculus or diseased/rough tooth/root surface. Finally, the ring and pinkie fingers are rested on a stable surface. Hand instruments are used with a gentle touch and are run over the tooth numerous times in overlapping strokes until the tooth feels smooth. This step may be performed with a curette and combined with subgingival scaling (see below).
Step 4: Subgingival Plaque and Calculus Scaling
This step is best performed by hand with a curette. A curette has 2 cutting edges and a blunted toe and bottom. The proper curette is selected based on its angulation. The lower the number (i.e., 1-2), the less the angle and the further rostral in the mouth the instrument is used. The face of the instrument is placed flat against the surface of the tooth and inserted gently to the base of the sulcus or pocket. Once there, the instrument is rotated so that the shaft is parallel to the long axis of the tooth. This will engage the calculus, as well as place the instrument in the proper position for root surface and subgingival debridement. This is repeated with numerous overlapping strokes until the root feels smooth.
Traditional ultrasonic scalers should not be used subgingivally due to thermal damage to the gingiva and pulp. This occurs because the water coolant cannot reach the tip of the instrument. However, sonic and ultrasonic scalers with specialized periodontal tips have been developed for subgingival use. Like supragingival scaling, it is recommended to perform mechanical scaling first to remove the majority of the plaque and calculus first, and then follow up with hand scaling.
Step 5: Polishing
Scaling leaves the tooth surface rough, which increases plaque attachment. Polishing will smooth the surface of the teeth, which will retard plaque attachment. Polishing is typically performed with a prophy cup on a slow-speed hand-piece with a 90-degree angle. The hand-piece should be run at a slow rate and no greater than 3,000 RPM. Ensure that adequate polish is used at all times. Running the prophy cup dry is not only inefficient, it may also overheat the tooth. Just like with scaling, every mm2 of tooth surface should be polished. One tooth may be polished for a maximum of five seconds at a time to avoid overheating.
Step 6: 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. A gentle lavage of the sulcus is strongly recommended. The lavage is performed with a blunt-ended cannula, which is placed gently into the sulcus and the solution is injected while slowly moving along the arcades.
Step 6 (a): Fluoride Therapy (Optional)
This is a controversial step, with some dentists recommending that it be performed in all cases and some that it never be done. The positive aspects of fluoride include antiplaque and antibacterial activities, hardening tooth structure, and decreases tooth sensitivity. The latter activity is most important in patients with gingival recession and secondary root exposure.
Step 7: Periodontal Probing, Oral Evaluation, and Dental Charting
This is a critical, however often poorly performed and underappreciated step. The entire oral cavity must be systematically evaluated using both visual and tactile senses. Careful visual examination should be performed during the periodontal evaluation. The periodontal probe should be inserted at six spots around every tooth to identify periodontal pockets. The normal sulcal depth in a dog is 0-3 mm, and a cat is 0-0.5 mm. All abnormal findings must be recorded on the dental chart.
Step 8: Dental Radiographs
Dental radiographs should be performed of any pathology noted on dental exam. This includes any periodontal pocket, which is larger than normal, fractured or chipped teeth, masses, swellings, or missing teeth.
Step 9: Treatment Planning
The practitioner, utilizing all available information (visual, tactile, and radiographic), then decides on appropriate therapy. Following the creation of a dental plan for the patient, an estimate is created and the client contacted.
This is a very important part of periodontal therapy. A recent study has shown that periodontal pockets are reinfected within 2 weeks of a prophylaxis if homecare is not performed. Therefore, homecare must be discussed with each client following a prophylaxis.
There are two divisions of homecare, active and passive. They both can be effective if performed correctly; however, active homecare is still the gold standard in homecare. Active homecare consists primarily of tooth brushing.
Frequency: once a day would be ideal, as this is required to stay ahead of plaque formation, but for most owners this is unrealistic. Three days a week is considered the minimum frequency for patients in good oral health. If the patient has periodontal disease, daily brushing is necessary. One other option for active homecare is to rinse with a chlorhexidine solution. Passive homecare is the other option for minimizing periodontal disease. Since this requires no work by the owner, compliance is more likely. There are currently several diets that decrease tartar and plaque build-up. In addition, tartar control chews and treats have been developed. All of these products have been shown to decrease plaque and calculus; however, they are most effective on plaque and tartar on the cusp tips, not at gingival margin.
The downfall of all passive homecare products is that the patient is not likely to chew with the entire mouth; therefore, areas will be missed. Passive homecare is most effective on the carnassial and surrounding teeth, where chewing is concentrated.
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, as well as smoothing the diseased root surface.
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.
Pockets greater than 5 mm 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.
The final modality for the therapy of periodontal disease is extraction. While extreme, it is the only true cure. Without a commitment to homecare or routine professional cleanings, advanced periodontal surgery should likely not be attempted. Depending on the stage of periodontal disease, the involved teeth should be extracted.