Periodontal disease is staged based on the amount of bone loss surrounding a tooth root. Should one root of a multirooted tooth have more bone loss than the other, the PD classification is based on the worst root. It’s also essential to note that attachment loss (AL) rarely equates to periodontal pocket depth (PP). Any root exposure (RE) and/or gingival enlargement (GE) should be noted.
In cases of root exposure, PP+RE = AL. For a video on the differences between curettes and scalers and their placement into the gingival sulcus, visit: https://tooth.vet/wvc-perio.
Keeping owner compliance and patient comorbidities in mind, along with tooth size variation, one can simplify PP measurements to guide treatment: • PP depths 1–4 mm should receive closed root planing
• PP depths ≥5 mm are best served by open flap debridement surgery for an average patient (5 mm may be normal in large breeds, while 3 mm may be problematic in small teeth/breeds).

One reason to consider open root planing, which usually extends into some form of flap and oral surgery, is that despite meticulous closed cleaning, residual plaque and calculus are still found at depths greater than 5 mm. In other cases, practitioners may rely on perioceutic medication under the false impression that antimicrobials alone resolve disease. The advantages to open flap treatments include:
• Direct root cleaning with visualization
• Resection of diseased pocket lining and soft tissue treatment
• Primary intention healing
• Evaluation and treatment of bony defects if present
• Minimal alveolar bone resorption during healing

In pockets with vertical bone loss, common on palatal aspects of maxillary canines, intrabony defects provide potential for regenerative procedures. Guided tissue regeneration (GTR) removes irritants (calculus, bacteria, granulation tissue, debris) to encourage PDL, bone, and cementum by excluding gingival tissues with a barrier. Many barriers and graft products exist, with new options entering the veterinary market each year. Familiarity with their properties and sources aids in product selection. Available products are listed at https://tooth.vet/wvc-perio Grafts vary in source and features. The most basic feature is osteopromotive: promoting new bone. They may also have osteoconductive surfaces whose topography permits and encourages cellular attachment and migration. Both osteopromotive and osteoconductive surfaces act as scaffolds. Materials are often augmented to be osteoinductive, containing growth factors that induce stem cells. Osteogenic materials contain living mesenchymal cells capable of forming bone (from the patient’s marrow). Almost all graft materials do not function as barriers/membranes. Recall that a barrier is required for GTR to prevent soft tissue in-growth.