Introduction
The extent of periodontal disease you might encounter in patients can vary from patient to patient and even from tooth to tooth in the same patient. From minimal inflammation and no attachment loss in Stage 1 Periodontal Disease to the beginnings of attachment loss (up to 25%) in Stage 2, then deeper pockets (up to 50% attachment loss in Stage 3) and even compromised teeth (greater than 50% loss) in Stage 4, you must be able to tailor the treatment to the problem. Beyond the dental cleaning, being able to provide advanced periodontal management for your patients is not only good medicine, but good business. By adding simple instruments, materials and skills to your dental armamentarium, you can identify and treat those teeth that may have been extracted in the past.

Therapy goals
When looking at periodontal disease, therapy is determined by a number of factors, such as the stage of the disease, the involved tooth, the client’s commitment and the desired outcome. There are several goals to set, including removal of all debris or biofilm (plaque, calculus), keeping the maximum amount of attached gingiva, minimizing attachment loss and minimizing the pocket depth. 1 Certainly, all foreign material, from bacteria to desquamated cells must be removed from the tooth surfaces and pockets in order to attain healing. Since the attached gingiva is the first line of defense against bacteria, a minimum of 2-3 mm is necessary to protect underlying tissues, as the looser alveolar mucosa doesn’t afford that protection. The inability to halt attachment loss will eventually lead to tooth loss. Minimizing pocket depth is related to attachment loss, but is a more specific parameter, because pocket depth in itself directly affects the ability for effective home care and maintenance, and deeper pockets can harbor more virulent strains of bacteria. There are even times where excessive gingiva will be removed to decrease pocket depth (hyperplastic gingiva) or the gingiva will be sutured further down the root (apically repositioned flap) for the same effect. Attachment loss without pocket formation occurs when gingival tissue and bone is lost at the same time, exposing the roots and even furcation areas. The ability to take intraoral radiographs is essential, in order to determine the extent and characteristics of bone loss. With recession of gingiva and bone across several roots and/or teeth, a horizontal bone loss pattern will often result in exposed roots. With a deeper osseous loss down one root surface, an infrabony pocket may result from the vertical bone loss, and specific therapy may be needed to address that specific defect. These deeper pockets are more difficult to treat and maintain, and anaerobic infections may persist.

Attachment Loss – Treatment Decisions
In evaluating teeth at either end of the spectrum – minimal disease with stage 1 or 2 teeth, or extensive stage 4 disease – the decision process is pretty straight forward. With stage 3 periodontal disease affected teeth – there is more of a challenge to decide whether to extract or try to save. The extent and type of attachment loss is a part of the decision process, as is the consideration of the relative importance of the tooth itself. Major teeth (canines, carnassials) will often be considered for advanced procedures, and adjacent, smaller teeth that are contributing to the infection should be considered for extraction, as their removal will allow better access to the strategic tooth. By extracting the middle tooth in the middle of three rotated, crowded premolars can often enhance the health of the remaining two teeth.

If the attachment loss results in root exposure with minimal pocket formation, professional cleaning and home care may be easier. Any involvement of the furcation puts the tooth at higher risk, due to challenges of continued care. If a pocket is present, it should be thoroughly evaluated: how deep is it? is it suprabony or infrabony?

Patient health status is also evaluated: patients with systemic disease would like benefit more from extraction with the immediate removal of the infection, and a decreased anesthetic time. Clients also are involved in the decision: advanced periodontal therapy requires excellent home care and more frequent professional visits.

Advanced Periodontal Therapy

Moderate Pocket Depths
With suprabony pockets (soft tissue only) of up to 5 mm in depth, evaluate not only the pocket, but the amount of attached gingiva left. If there is 7mm of attached gingiva due to inflammation or gingival enlargement, a simple gingivectomy/plasty can immediately reduce the pocket depth to a more manageable level. A 12-fluted bur on a high-speed hand-piece is extremely helpful with minor trimming. If there is minimal gingival enlargement and only 2-3 mm of attached gingiva, then closed root planing and placement of a perioceutic can provide excellent care for the defect.

Root planing/ subgingival cleaning
This is by far the most important aspect of periodontal therapy. If the debris is not thoroughly removed from the pocket depths, the disease will remain and intensify. The rounded tip of the curette, and it’s rounded back, makes it ideal for subgingival therapy, as opposed to the sharp tip and back of a hand scaler. Certain ultrasonic scalers are modified for subgingival treatments, but most are not. If root surfaces are exposed, or if the pocket depth is less than five mm, closed root planing and subgingival curettage may be performed. Using a curette subgingivally with overlapping strokes in horizontal, vertical and oblique directions, root planing removes calculus, debris and necrotic cementum to provide a clean, smooth surface. Root planning that is too aggressive can damage the root, so take some care. The curette can also be angled slightly to engage the gingival surface for removal of diseased or microorganism-infiltrated tissues, but again, not too aggressively. When pocket depth exceeds 5 mm, or other pathology exists, more invasive procedures are warranted.

Perioceutic therapy
In moderate pockets of up to 5 mm in depth (and generally deeper than 2 mm), once the area is debrided, placement of a local perioceutic medicaments can be considered. The combination of the cleaning and therapy can often help reduce the pocket depth in moderate situations. A gel containing doxycycline hyclate can not only provide a direct antibacterial affect against any remaining bacteria, but the anticollagenase activity can help “rejuvenate” the soft tissue of the pocket. A clindamycin gel may also be considered. A hyaluronic acid gel is now available in the US as well.

Surgical Periodontal Therapy
Many standard pieces of equipment and supplies can be used, including scalpel blades (15C works well), scissors (sharp/sharp for gingival remodeling), and sutures (usually absorbable, from 3-0 to 5-0). It is important to have other equipment as well for unique oral situations, including periodontal curettes for scaling root surfaces and periosteal elevators (Molt No. 2 or No.4) for elevating gingival flaps. For minor gingivectomy/gingivoplasty, a 12-fluted bur on a high-speed hand-piece can be helpful.

When pocket depths exceed 5 mm but remain above the level of the bone, a simple envelope flap allows access and improved visibility for open curettage and root planing. That deep of a pocket will usually lead to a consideration of extraction, unless the tooth is a strategic one (canine tooth, carnassial tooth). Exposing the area with a gingival flap (scalpel blade inserted into the sulcus, sometimes with a releasing incision, and elevation with a periosteal elevator) allows thorough evaluation and debridement. The flap can then be sutured back into place, or to a position further apical on the root, more directly over the bone, to reduce the pocket depth.

If the pocket extends down between the root and alveolar bone (infrabony defect) inadequate therapy can lead to even further attachment loss and even tooth loss. Just cleaning the area will often lead to the soft tissues (gingival epithelium, gingival connective tissue) growing back into the defect faster than the more important supportive tissues of the periodontium (alveolar bone, periodontal ligament). Placing bone graft material and barrier membranes can actually help exclude the soft tissue and allow bone to grow back into the defect (guided tissue regeneration).

If an adjacent, smaller tooth is involved in the area of attachment loss, its extraction is sometimes the best way to get access to the larger, more strategic tooth’s surfaces. The releasing incision is made away from the tooth being treated, allowing a complete attached gingival coverage of the treated site. Extraction of the middle of three crowded teeth also allows better exposure and treatment of the remaining teeth.

Regenerative Therapy
There are several indications for practical application of regenerative periodontal therapy. Vertical bone loss at the distal root of the mandibular first molar, at the palatal or mesial aspect of the maxillary canines, and mesial or lingual intrabony pockets of the mandibular canines can all be effectively treated to fill in the osseous defects. If there is no apical involvement, oronasal fistulation, and adequate exposure can be afforded (extract adjacent teeth, flaps), complete debridement of the defect with placement of a variety of materials, including placement of membranes, can help save these critical teeth and even strengthen the associated mandible or avoid fistulation.

The site for attempted GTR needs a biocompatible root surface, presence of healthy precursor cells (osseous ‘walls’), exclusion of surface tissues and stabilization of the wound and clot. The morphology of the pocket (walls and angle of defect) and access to the defect are factors in selection and prognosis. A 4-wall or cup defect may provide the most osseous surface area but will be challenging to debride; a wide defect may provide better access but will have a broader expanse to repopulate.
Once a deep infrabony pocket is cleaned, typically the soft tissues (gingival epithelium, gingival connective tissue) will grow back into the defect faster than the more important supportive tissues of the periodontium (alveolar bone, periodontal ligament). By placing a barrier between the instrumented root surface and the gingival flap, it can act as a deterrent to exclude the gingival epithelium or gingival connective tissue from populating the root structure. This barrier then provides an area for the progenitor cells of the periodontal ligament and/or alveolar bone to have free access for migration.

Bulk materials in the form of bone graft material can be used alone but can be maximized with a barrier membrane. An osteoconductive material provides a scaffold that can ‘promote’ (Consil) the cellular attachment, proliferation and migration, often with substances that enhance osseous response. Alloplasts (synthetic material) are incorporated into the bone while products with demineralized freeze-dried bone (DFDB - Osteoallograft) can be resorbed quickly. An osteointegrative material can take a product with DFDB and go one step further, using BMP (bone morphogenic proteins) to allow a direct structural and functional connection with living bone. Osteoinductive products are biological materials with growth factor or graft material that helps lead the differentiation of mesenchymal stem cells into osteoblasts. Products that stimulate osteogenesis from any tissue or cell capable of differentiation can aide in the development, growth or repair of bone.

The origins of materials also play a part, with autogenous bone from the same individual being harvested from intraoral or other sites providing a variable osteoinductive response. Allogenic bone from the same species is often a DFDB product and likely provides osteoconductive and possibly osteoinductive impact. Xenografts have been developed with bone from different species, but are not significantly better than open root planing and home care in human studies. Alloplasts are biosynthetic materials than only provide osteoconductivity as a scaffold and may be considered more for a bone fill.

A new gelatin-based tissue scaffolding (ReGum Vet®) utilizing a proprietary Cell-Foam™ technology, with injectable and solid forms (cones and small sheets). It fills and supports the defect, providing a framework for tissue repair. It is resorbed and replaced with the tissue during the healing process. Cases have shown bone fill and there are options for using it in furcation defects. The hyaluronic acid gel may also be considered (PerioVive®)

Barrier membranes on their own can inhibit rapid epithelial growth but can sometime result in a long junctional epithelium, so are often used in conjunction with bulk materials (see above). The earliest membranes were synthetic and non-resorbable, requiring removable and are used now primarily for guided bone regeneration. Resorbable, biodegradable and some natural membrane (Ossiflex – DFDB) materials are more frequently used, from vicryl based materials to those using collagen, and even made chair-side with perioceutic gels (Doxirobe).

Biological products are now frequently used in conjunction with barriers (bulk and membrane) to enhance the regeneration of tissues. Growth factors such as BMP (bone morphogenic protein) with osteogenic proteins can help induce mesenchymal progenitor cells to become osteoblasts. Autologous platelets and pellets provide platelet-derived growth factors that can be added to autologous bone graft to help increase the quality of bone regeneration, especially in larger defects with lower osteogenic potential. Even enamel matrix derivatives (EMD) from porcine tooth protein help promote fibroblasts that can result in new cementum, PDL and bone, similar to GTR with membranes, but with unpredictability among batches.

Two sites that are most commonly selected for GTR involve the distal root of the mandibular first molar (often with extraction of the second molar for exposure) and the palatal aspect of the maxillary canine, before the defect results in an oronasal fistula. An essential key to such a procedure is adequate exposure and debridement of the area. A gingival flap is necessary to allow for thorough curettage of all material in the infrabony pocket in between the tooth and root, including the removal of any granulation tissue. Once healthy bone and tooth surfaces are clean, the bone graft material is packed into the defect, the membrane placed, and the gingival closed over it. Post operatively vigorous home care and plaque control are essential.

Specific Conditions

Mandibular Canines and Incisors
The mandibular incisors are frequently affected by periodontal disease and bone loss, especially in smaller dogs. It is tempting just to wiggle out a loose tooth, and that will remove the primary source of the disease, but leaving the involved, less healthy soft tissues can continue to impact adjacent teeth, especially the mandibular canines. The bone loss between the mandibular third incisor and canine can result in a persistent deep soft tissue pocket (with some intrabony extension) once the incisor is gone. A deep soft tissue pocket may also be present around the mandibular canine if the tooth is not fully erupted, as gingiva cannot attach to the enamel that is still below the gum line. Persistent pockets here can predispose the canines to additional periodontal disease with anaerobic plaque bacteria present.

In order to minimize these pockets, the soft tissue linings often have to been excised, and the level of the gingival margin may have to be moved further apically down the tooth. A wedge excision of the tissue from the mesial margin of the canine (the surface closest to the midline of the symphysis) helps remove the excess and granulomatous tissue, and can minimize the pocket depth if the height is reduced (if sufficient attached gingiva remains). With partially erupted teeth, the wedge incision may not be enough: the attached gingiva may have to be elevated past the muco-gingival junction to release the flap at the level of the looser alveolar mucosa. This way the flap can be repositioned further apically on the tooth and secured with sutures, revealing more of the crown and decreasing the pocket depth. In other teeth, trimming the gingiva or securing the margin further apically will actually expose more root surface, but root exposure is simpler to keep clean that a root within a pocket.

Mandibular First Molar
Any attachment (bone) loss at the mandibular first molar deserves attention. Advancement of bone loss at this tooth is one of the most common reasons for pathological fracture of the mandible. Bone loss at the mandibular fourth premolar or second molar, particularly if vertical bone loss has started at the first molar, is sufficient reason to extract the smaller tooth to provide access to treat the first molar more effectively. For best periodontal treatment, a releasing flap is made at the furthest margin of the adjacent tooth to be extracted, with the gingiva elevated to facilitate extraction, and thus exposure of the affected root of the first molar. Any pocket lining or granulation tissue in the region should be removed, and the area scaled until healthy root and bone is exposed. If there is an intrabony pocket around the first molar, a bone graft material can be placed, as well as in the alveolus of the extracted tooth. At the very least, the disease tissue should be removed, the root cleaned thoroughly, and the gingiva sutured closed around the first molar.

Maxillary Premolars
In smaller dogs and brachycephalic breeds, maxillary premolars can often be crowded, sometimes with significant rotation that stack them up on each other. The lack of healthy bone in between these teeth predisposes them to additional periodontal attachment loss, and it can be challenging to keep them healthy. While some propose prophylactic extraction of any rotated and crowded maxillary premolars, in most patients, regular examination and cleaning can alert the practitioner to those that may require extraction. Often, the ‘middle’ tooth in a series of three teeth can be extracted to improve the condition of the two adjacent teeth. Special attention should be paid to the maxillary third premolar, for if the distal root is crowded between the two mesial roots of the fourth premolar, the third premolar may need to be sacrificed.

As a strategic tooth, it is often worth it to provide additional effort to preserve the health of the maxillary fourth premolar. In smaller dogs, it is critical to evaluate the status of the periodontal tissues around the palatal root. It is often so small, that a 3-4 mm pocket with bone loss can completely envelope the root, compromising the entire root. In fact, an infraorbital swelling in a small dog with an intact (not fractured) fourth premolar should lead a close examination of the palatal root.

Maxillary canines
Periodontal bone loss at the palatal aspect of maxillary canines can lead to oronasal fistulae, once a deep pocket extends past the level of the palatal bone. Once formed, the fistula is nearly impossible to correct, so extraction is necessary. Chronic fistulation can be challenging to close, as every breath puts tension on the sutured flap. Prevention of fistulation is critical, so careful evaluation of the palatal (and mesiopalatal aspect) of the maxillary canine is important. If a moderate pocket is formed, closed root planning and a perioceutic may help stop the progression. If an intrabony pocket has formed, there may an opportunity to provide advanced periodontal treatment for guided tissue regeneration to build back the lost bone before the fistula is formed.