Periodontology
What this domain tests
This domain tests periodontal etiology, diagnosis, staging and grading, nonsurgical and surgical therapy, and maintenance. Items often require interpreting probing depths, clinical attachment loss, bleeding, and radiographs together.
Core rules and concepts
- Periodontitis is biofilm-induced, but host response, smoking, diabetes, and genetics modify severity and progression.
- Gingivitis is reversible inflammation limited to the gingiva. Periodontitis requires clinical attachment loss and radiographic bone loss.
- Staging reflects severity and extent; grading reflects progression rate and risk. Do not diagnose periodontitis from probing depth alone.
- Nonsurgical therapy includes oral hygiene instruction, scaling and root planing, risk-factor control, and re-evaluation after about 4 to 6 weeks.
- Surgical therapy is considered for residual pockets, regenerative needs, or access after initial therapy. Regeneration is most predictable in contained defects.
- Maintenance intervals are individualized, often 3 to 6 months. Smoking cessation and glycemic control improve outcomes.
- Antibiotics are adjuncts, not substitutes for debridement. They are reserved for specific situations such as aggressive or severe disease with systemic involvement.
Worked example
A 45-year-old smoker has 6 mm pockets, bleeding on probing, and 30 percent bone loss. The reasoning is periodontitis stage III grade C, with smoking increasing risk. Start with oral hygiene instruction, scaling and root planing, and cessation counseling; re-evaluate before deciding on surgery. Giving antibiotics alone without debridement would not address the biofilm and calculus.
Traps that cost marks
Do not use probing depth alone as the diagnosis. Smoking can mask bleeding on probing. Gingivitis is reversible, but treated periodontitis needs maintenance. Antibiotics are not a substitute for mechanical therapy. Also distinguish peri-implantitis from periodontitis by implant-specific findings.