Periodontology
Core concepts
Know the anatomy of the periodontium and the clinical parameters: probing depth, clinical attachment level, bleeding on probing, plaque index, recession, and mobility. Understand the 2017 World Workshop classification - periodontal health, gingivitis (plaque-induced, non-plaque-induced), periodontitis (staging I–IV by severity and complexity, grading A–C by rate of progression and risk), and the peri-implant categories (peri-implant health, mucositis, peri-implantitis). Know the pathogenesis: dysbiotic plaque biofilm, host inflammatory response, the role of risk factors (smoking, diabetes, poorly controlled glycaemia, genetic factors, medications), and the concept that periodontitis is a chronic inflammatory disease with systemic associations (cardiovascular disease, diabetes, adverse pregnancy outcomes).
Know non-surgical periodontal therapy (scaling and root planing, oral hygiene instruction, risk-factor control, re-evaluation at 6–8 weeks) and surgical therapy (flap surgery, regenerative techniques with bone grafts and membranes, guided tissue regeneration, resective procedures). Know mucogingival surgery (free gingival graft, connective tissue graft, coronally advanced flap) and crown lengthening. Know antibiotic adjuncts (amoxicillin plus metronidazole in aggressive/grade C disease) and the principle that antibiotics are adjunctive, never a substitute for mechanical debridement. Know maintenance (supportive periodontal care intervals) and the risk of recurrence.
Traps
- Staging is about severity and complexity; grading is about rate of progression and risk.
- Bleeding on probing is a marker of inflammation, not of disease severity alone.
- Peri-implant mucositis is reversible; peri-implantitis involves bone loss and is not.
- Antibiotics without debridement are inappropriate.
Rule of thumb
Re-evaluate 6–8 weeks after non-surgical therapy before deciding on surgery; if bleeding on probing persists at ≥4 mm sites, the patient is not yet stable.