Periodontal cases: The basics

Gingivitis – Stage 1

Gingivitis is the beginning stage of periodontal disease in which inflammation is confined to the gingival soft tissues only. This inflammation does not clinically extend into the alveolar bone, periodontal ligament, or cementum. Gingivitis can be present without periodontitis. Periodontal disease can exist without gingivitis in an area of previous periodontitis that has been treated and controlled, relieving inflammation but not attachment loss.

Periodontitis – Progression of Gingivitis

Periodontal disease is the most common oral disease in dogs and cats. It is important to understand the cause, diagnosis, and treatment options based on assessment to be successful with periodontal treatment.


Within minutes of teeth scaling and polishing, a layer of glycoprotein (acquired pellicle) attaches to the exposed crown surface. Hours later, aerobic and facultative anaerobic bacteria (including Actinomyces and Streptococcus) colonize the glycoprotein layer, forming plaque. Calculus is formed by mineralization of plaque and food debris. Calculus is covered with bacteria, thus playing a role in maintaining and accelerating periodontal disease by keeping plaque in close contact with the gingival tissues and decreasing the potential for repair and new attachment.

The progression of periodontal disease is dependent on the complex regulatory interaction between bacteria and immune modulators of the host response. Animals that have compromised health often cannot fight periodontal pathogens

Early periodontitis - Stage 2 (PD2)

Occurs when there is less than 25% loss of attachment of alveolar bone on the root. At most, stage 1 furcation involvement exists.

Periodontal therapy for stage 2 early periodontitis includes removing irritants and debris from the tooth surfaces and periodontal pockets through subgingival and supragingival dental scaling. Pocketing defects can be treated with locally administered antimicrobials.

Moderate periodontitis - Stage 3 (PD3)

Occurs when there is between 25-50% tooth support loss. Treatment includes thorough dental scaling both above and below (up to 5 mm) the gingival margin. For pockets deeper than 5 mm, surgical flap exposure can be performed to allow access to remove plaque and calculus from the root. Placement of a local antibiotic can help rejuvenate periodontal tissues and may reduce pocket depth. Extraction of the affected tooth is recommended in cases where stringent plaque control will not be accomplished.

In cases where there is marked gingival recession, mucogingival surgery can be performed to decrease the rate of disease progression. A lateral sliding flap can be used to cover the exposed defect.

Advanced periodontitis - Stage 4 (PD4)

Occurs when greater than 50% support loss is diagnosed. In cases of moderate and advanced periodontal disease, surgery is usually indicated to either (1) extract the tooth (teeth) where the client will not agree to home care for ongoing plaque control, or (2) provide mucogingival surgery to decrease pocket depth.

For more information, visit AAHA Dental Care Guidelines for Dogs and Cats.

This content is authored by Jan Bellows, DVM, DAVDC, DABVP, ALL PETS DENTAL, Weston, Florida.