Periodontal Disease and Periodontal Therapy
Diagnosis before treatment
Gingivitis is reversible inflammation confined to the gingiva with no clinical attachment loss; periodontitis requires clinical attachment loss plus radiographic bone loss. The 2017 classification separates stage (severity and complexity: CAL, probing depth, bone loss percentage, tooth loss, furcation, ridge defects) from grade (rate of progression: A slow, B moderate, C rapid, based on direct radiographic evidence or indirect evidence such as bone loss divided by age, plus smoking and HbA1c ≥7%).
Charting traps are frequent. A pseudopocket from gingival enlargement has no attachment loss. CAL equals probing depth plus recession when the margin is apical to the CEJ, and probing depth minus the coronal margin position when the margin is coronal to the CEJ. Bleeding on probing confirms inflammation but its absence has strong negative predictive value for future attachment loss.
Therapy sequence: risk-factor control and self-care instruction, then nonsurgical periodontal therapy (scaling and root planing, with local anesthesia for deeper pockets), then re-evaluation at 4–6 weeks before deciding on surgery or maintenance. Systemic antibiotics (amoxicillin plus metronidazole) are adjuncts for grade C or specific conditions, never monotherapy. Supportive periodontal therapy intervals follow risk - typically 3 months for high-risk patients.
Worked example: probing depth 6 mm with the margin 2 mm coronal to the CEJ gives CAL = 4 mm; the same 6 mm depth with 2 mm of recession gives CAL = 8 mm. Trap: "probing depth alone diagnoses periodontitis" is false - attachment loss is required.