ABP Periodontology cheat sheet

Gingival sulcus depth in health is typically 0.5-3 mm; probing depth ≥4 mm with bleeding indicates pocket formation and possible attachment loss.

Clinical attachment level (CAL) = probing depth + gingival margin recession (relative to the CEJ); CAL is the reference standard for measuring past attachment loss.

Gingivitis is reversible inflammation confined to the gingiva with no attachment loss; periodontitis requires demonstrable CAL or radiographic bone loss.

The 2018 classification stages periodontitis by severity (Stage I-IV) using interdental CAL, radiographic bone loss, and tooth loss, and grades it (A-C) by progression rate using bone loss/age ratio.

Bone loss/age ratio: Grade A <0.25, Grade B 0.25-1.0, Grade C >1.0; grade reflects rate of progression and modifies staging.

Plaque-induced gingivitis is the most common form; systemic modifying factors (pregnancy, puberty, diabetes, medications) amplify the gingival response.

Aggressive (now Grade C) periodontitis features rapid attachment loss, familial aggregation, and often molar-incisor pattern in younger patients.

Necrotizing periodontal disease triad: papilla necrosis, ulceration, and pseudomembrane formation, often with fetor oris and pain.

Risk factors with strong evidence: smoking, poorly controlled diabetes (HbA1c), and specific microbial complexes (red complex: P. gingivalis, T. denticola, T. forsythia).

Osseointegration is direct structural and functional connection between living bone and implant surface without intervening soft tissue; requires primary stability and undisturbed healing.

Minimum bone volume generally needed: ~1-2 mm buccal/lingual bone around implant and adequate apico-coronal height; 2 mm between adjacent implants is a common guideline.

Implant survival vs success: survival = implant still present; success adds criteria (no mobility, no peri-implant radiolucency, bone loss <0.2 mm/year after first year, no pain/infection).

Peri-implant mucositis is reversible inflammation of soft tissue with no bone loss; peri-implantitis adds progressive bone loss and is not predictably reversible.

Sinus lift: crestal approach for ≥5 mm residual bone; lateral window for <5 mm residual alveolar bone height before implant placement.

Implant loading timing: immediate (same day), early (1-2 weeks to 3 months), conventional/delayed (>3 months); choice depends on primary stability and bone quality.

Bone density (Lekholm-Zarb or Misch) affects drilling protocol: denser bone (D1) needs more irrigation and tapping; soft bone (D4) risks inadequate primary stability.

Smoking and uncontrolled diabetes increase implant failure and peri-implantitis risk; smoking cessation counseling is standard pre-operative management.