Periodontal therapy ("prophy") involves the inspection of the periodontium and charting of the teeth, probing of the gingival sulcus, supra- and subgingival scaling and root planing. It is followed by polishing and homecare advice. It cannot be done without a treatment plan, nor can it be done quickly.
The steps involved in the complete periodontal therapy are:
Periodontal probing and charting
Recording of all findings and development of a treatment plan
Gross removal of supragingival plaque and calculus
+/- Periodontal surgery and open root debridement
Polishing for removal of more plaque
Antimicrobial treatments, i.e., perioceutics
The use of osteoinductive agents to regain attachment loss
Homecare advice and instructions
Recall and review
1. Periodontal Probing and Charting
As periodontitis is a disease of the periodontium and involves the loss of periodontal attachment to the tooth, the only way to assess this loss or its reattachment (the gain of attachment is the aim of periodontal treatment) is by assessing the extent of disease (by probing and intraoral radiography) and recording this information.
2. Intraoral Radiography
Dental radiography allows one to assess the bone height surrounding the tooth, and this gives an indication of attachment loss and the severity of periodontal disease. Alveolar bone loss is not seen with gingivitis. Intraoral radiographs may show horizontal or angular (vertical) bone loss associated with periodontitis.
Radiography can also reveal subgingival calculus deposits, as well as other forms of pathology such as periapical lesions, tooth resorptions, and tumours both of soft and hard tissues.
Angular (infrabony) bone loss is classified as: a one-wall bony defect (limited by one osseous wall and the tooth surface); two-wall infrabony defect (limited by two osseous walls and the tooth surface); and a three-wall infrabony defect (limited by three osseous walls and the tooth surface).
3. Recording and Treatment Planning
The periodontal probing depths are recorded on a dental chart along with any other abnormalities, such as missing, fractured, rotated, and crowded teeth; persistent deciduous teeth; and an assessment of the gingival health including its colour, contour, and consistency. Probing depths of 1–3 mm are normal in the dog, whereas 0–1 mm are normal in the cat. Periodontal probes are used with light pressure and placed parallel to the root surface.
After all abnormalities, including gingival recession, probing depths, and loss of attachment have been recorded, one can then formulate a treatment plan that takes into account individual teeth, the dentition as a whole, and the ability of the owner to perform homecare.
The primary role of treatment is to remove plaque and to formulate a plan that will prevent or slow down its reformation.
4. Gross Removal of Supragingival Plaque and Calculus
The gross removal of calculus with a purpose-made calculus removal forceps aids in the speedier removal of smaller deposits by mechanical scalers.
5. Supra-/Subgingival Debridement
The removal of supra- and subgingival plaque is achieved by a combination of mechanical scaling and hand scaling. There are two forms of mechanical scalers. The ultrasonic scaler is the most widely used. Ultrasonic scalers include the magnetostrictive scaler ('Cavitron' type) and the piezoelectric scaler.
Magnetostrictive instruments operate between 18,000–45,000 cycles per second (Cps). When an electrical current is applied to a wire coil in the handpiece, a magnetic field is created around the stack or rod, causing it to constrict. An alternating current causes an alternating magnetic field, resulting in tip vibration. The tip movement of magnetostrictive scalers ranges from linear to elliptical or circular, depending on the type of unit and shape and length of the tip. Magnetostrictive tip movement allows for activation of all surfaces of the tip at once. Water spray is essential to dissipate heat as well as producing cavitational activity within the water. This cavitation effect disrupts bacterial cell walls and can operate slightly beyond the reach of the tip (a benefit when used in deep pockets).
The piezoelectric scaler has crystals within the handpiece that undergo dimensional change. The piezoelectric unit operates at 25,000–50,000 Cps with a linear tip movement, and only two sides of the tip are active at any one time. Piezoelectric scalers tend not to heat up as much as magnetostrictive scalers.
A ferro-magnetostrictive scaler (42–12 iM3 Veterinary Dental Company) is now available in the veterinary market; it has more of a circular tip movement and, due to its water delivery system, allows for subgingival scaling even into deep pockets without the risk of iatrogenic thermal injury to the tooth.
The other form of scaler is the sonic scaler. Sonic scalers are air turbine units that operate between 3,000–8,000 Cps. They are used less often in veterinary dentistry than ultrasonic scalers, mainly due to their expense and their slowness in removing plaque and calculus. Their benefits include lower heat production (thus reducing the chance of thermal injury to the pulp) and reduced tooth surface damage when compared to ultrasonic scalers.
Scalers should be held so the long axis of the scaler tip is parallel with the tooth surface, so as to prevent the concentration of heat in one area or gouging the tooth. One should not spend more than 15 seconds on any one tooth at a time.
Light sweeping strokes with minimal pressure should be employed. The use of the modified pen grasp and finger rests is recommended.
The fine spray that develops with the use of mechanical scalers is laden with bacteria. It is recommended that face masks and protective eyewear be worn at all times to protect the operator and assistant.
Some mechanical scalers can be used subgingivally so long as they are used for short periods of time and there is adequate water cooling. Subgingival cleaning also requires a reduction in the power setting on the scaler (check with the manufacturer regarding the best power setting for subgingival cleaning).
Hand scalers are then used to remove any remaining plaque and calculus.
The H6–H7 sickle scaler is ideal for supragingival plaque removal. Curettes are used for supra- and subgingival scaling. Curettes come in a number of types. Gracey curettes are popular choices for subgingival scaling and root planing. Curettes remove necrotic cementum and plaque as well as calculus.
Overlapping strokes, when hand scaling, are used so as to remove as much calculus and plaque as possible.
It is imperative to ascertain the thoroughness of subgingival scaling by probing the gingival pocket after scaling for any remaining deposits and re-scaling if necessary.
With any form of hand scaling, the instruments must be sharp. Therefore, it is important to sharpen these instruments during and after hand scaling in order to give the best results.
6. +/- Periodontal Surgery and Open Root Debridement
Open curettage is reserved for deeper pockets (> 4 mm).
The consensus of opinion favours the use of closed curettage first, and then if on subsequent reassessments of the gingival pocket, if periodontal attachment has not been stabilised or regained, then open curettage should be considered. Open curettage involves the raising of a gingival flap, hand or mechanical scaling, and then replacing the flap in its original position or more apically, so as to reduce the pocket (apically repositioned flap).
After scaling and root planing has been performed, polishing of the tooth surface is carried out with the use of a slow-speed handpiece, prophy head, polishing cup, and polishing paste (abrasive).
The aim of polishing is mainly to remove any residual plaque, but polishing will help smooth over any exposed root surface. It is important to always have polishing paste on the rubber cup to avoid thermal injury to the tooth.
8. Sulcular Lavage
It has been shown, through a number of human studies, that sulcular lavage is not necessary.
The flow of gingival fluid from the sulcus is enough to dislodge any unattached debris. Removal of prophy paste and other debris can be done by the use of the air/water spray on the triplex syringe.
9. Antimicrobial Treatments
Chlorhexidine gluconate (0.12%) is a broad-spectrum antimicrobial with excellent efficacy in the oral cavity. It requires at least one-minute contact time with the oral tissues to be effective, but it has good substantivity (persistence of action) and will last for a number of hours in the mouth.
Chlorhexidine gluconate can be used as a pre-prophy wash to reduce the amount of oral bacteria and hence decrease the bacterial aerosol and the risk to the operator/assistant, which can occur during scaling.
Chlorhexidine gluconate can be used as a long-term chemical plaque retardant in the dog. It is a broad-spectrum antimicrobial with excellent efficacy in the oral cavity. Bacterial resistance to chlorhexidine gluconate is unlikely, as opposed to potential resistance associated with systemically or locally delivered antimicrobials.
The use of systemic antimicrobials should be reserved for procedures that involve gingival surgery or surgical exodontia, although systemic antimicrobials can be used for short-term improvement in periodontal disease.
The advent of local-delivery antimicrobials (perioceutics) offers another approach to the management of difficult-to-clean deep periodontal pockets.
10. The Use of Osteoinductive Agents and Guided Tissue Regeneration
Osteoinductive materials take part in the formation of new bone by offering growth factors and mesenchymal cells. Osteoconductive materials offer a scaffold for the in-growth of osteogenic cells.
11. Plaque-Reduction Strategies and Homecare Instructions
This is an integral part of the dental prophylaxis, because without it, the plaque and calculus would quickly return.
Homecare needs to be tailored to the needs of the animal and the compliance of the owner.
For homecare to work, one needs a firm and continuing commitment from the owner, but also advice from the veterinarian that is seen to be practical and realistic. Unwilling owners or head-shy pets make for an unrewarding and fruitless exercise.
The aim of homecare is the removal of plaque. However, the periodic disturbance of subgingival plaque and the removal of plaque from areas that cannot be accessed by proper homecare (i.e., furcation sites) should be performed on a regular basis under general anaesthesia by the veterinary dentist.
In 1997, the Veterinary Oral Health Council (VOHC) was established to offer a seal of acceptance to those oral hygiene products that were shown in controlled studies to retard plaque and calculus. Today, the VOHC Seal of Acceptance system for plaque- and tartar-control products is endorsed by a number of veterinary dental organisations throughout the world. A list of endorsed products can be found at the VOHC website: www.vohc.org
12. Recall and Review
The veterinary dentist should advise a revisit for the patient within six months of the prophylaxis treatment, to reassess the success of homecare and to establish the time intervals between professional scaling and cleaning. As a general rule, gingivitis patients should be seen every 6–12 months. Periodontitis patients need to be reviewed every 3–6 months.