Periodontics
What the exam expects
This domain tests periodontal anatomy, etiology, diagnosis, classification, nonsurgical and surgical therapy, and maintenance. Expect items that ask you to interpret probing depths, attachment loss, bleeding on probing, and radiographic bone levels together.
Core concepts to master
- Anatomy and histology: junctional epithelium, gingival fiber groups, biologic width, and the difference between gingival margin, probing depth, and clinical attachment level.
- Etiology: biofilm as the primary cause, risk factors (smoking, diabetes, genetics, medications), and the host response.
- Classification: staging (severity and complexity) and grading (progression risk) rather than the older chronic/aggressive labels.
- Therapy: scaling and root planing, adjuncts, systemic and local antibiotics, flap surgery, regeneration, and mucogingival procedures.
- Maintenance: recall intervals, risk-based reassessment, and the role of compliance.
Traps
- Equating probing depth with attachment loss; recession means attachment loss exceeds pocket depth.
- Assuming antibiotics replace mechanical debridement; they are adjuncts.
- Forgetting that smoking and poorly controlled diabetes are the strongest modifiable risk factors and worsen grading.
- Misapplying biologic width concepts to justify crown lengthening without measuring.
Rule of thumb
Compute attachment level as probing depth plus recession (or minus hyperplasia) and always report bleeding on probing with it. Worked example: a molar has a probing depth of 5 mm and 3 mm of recession; clinical attachment level is 8 mm, indicating significant attachment loss, so the correct staging reflects severity rather than the 5 mm pocket alone.