Periodontics
Periodontics is written in 2017 world workshop language, so examiners expect staging and grading vocabulary alongside classic clinical signs.
Classification logic
- Stage reflects severity and complexity: Stage I clinical attachment loss 1-2 mm, Stage II 3-4 mm, Stage III 5 mm or more with bone loss to the middle third and up to 4 teeth lost, Stage IV with 5 or more teeth lost or masticatory dysfunction.
- Grade reflects rate and risk: radiographic bone loss divided by age; under 0.25 is Grade A, 0.25-1.0 is B, over 1.0 is C; smoking and HbA1c are modifiers, not stages.
- Gingival health versus plaque-induced gingivitis rests on bleeding on probing with no attachment loss.
Non-surgical and adjuncts
- Supra- and subgingival instrumentation with oral hygiene instruction is the foundation for every stage.
- Systemic antibiotics such as amoxicillin plus metronidazole are adjuncts for Grade C or necrotising disease, never a substitute for debridement.
- Glycaemic control and smoking cessation change outcomes more than any single instrument.
Surgical and mucogingival care
- Access flaps, resective surgery and regeneration with grafts or membranes for intrabony defects; furcation involvement graded I-IV with different prognoses.
- Crown lengthening needs about 3 mm from the restorative margin to bone.
- Miller or Cairo classification for recession; a thin phenotype and shallow vestibule predict recurrence.
Worked example
A 46-year-old smoker with 20 pack-years and HbA1c 8.4% has interdental attachment loss of 6 mm, 50% bone loss on the mandibular first molars and has lost two teeth. Bone loss divided by age is about 1.1, so this is Stage III, Grade C. Treatment is counselling plus full-mouth instrumentation, then reassessment at 8-12 weeks before any surgery, with antibiotics only as an adjunct.
Traps
Staging by pocket depth alone; forgetting that grade requires age-based bone loss; prescribing antibiotics as primary therapy; missing furcation involvement because a curved probe was not used.