Periodontics
Diagnosis first
The 2017 classification replaced chronic and aggressive periodontitis with staging (severity and complexity, I–IV) and grading (rate of progression, A–C). Staging rests largely on interdental clinical attachment loss: Stage I up to 2 mm, Stage II 3–4 mm, Stage III 5 mm or more, with Stages III and IV adding complexity such as probing depths of 6 mm or more, furcation involvement, ridge defects, and tooth loss from periodontitis. Grading uses the ratio of bone loss to age plus risk factors such as smoking and diabetes.
Concepts to own
- Plaque-induced gingivitis is reversible and confined to the gingiva; periodontitis requires attachment loss.
- Bleeding on probing has a high negative predictive value: its absence is a reassuring sign of stability, while its presence alone is not diagnostic.
- Distinguish pseudo-pocketing from gingival enlargement versus true attachment loss.
- Risk factors: smoking, poorly controlled diabetes, medications, hormonal changes, and occlusal trauma as a modifier rather than a cause.
- Nonsurgical therapy comes first: oral hygiene instruction, scaling and root planing, then re-evaluation at 6–8 weeks. Adjunctive antibiotics never replace debridement.
- Surgical options include flap access, regenerative grafting, crown lengthening, and mucogingival procedures; supportive periodontal therapy intervals are set by risk.
Traps
Questions blur pocket depth with attachment loss. A deep pocket plus recession means more attachment loss than the probing depth suggests. A 5-mm pocket that never bleeds is not equivalent to a bleeding 5-mm pocket.
Rule of thumb
When the gingival margin is apical to the cementoenamel junction, clinical attachment loss equals probing depth plus recession.