Regenerative and Reconstructive Periodontics
Regenerative and Reconstructive Periodontics
The exam separates what regenerates predictably from what merely fills a space, and tests defect selection.
Core rules
- Guided tissue regeneration (Nyman, Karring, Gottlow): a barrier excludes epithelium and gingival connective tissue so PDL and bone cells repopulate the defect.
- Grafts: autograft (gold standard, donor-site morbidity), allograft (FDBA osteoconductive; DFDBA weakly osteoinductive), xenograft (slow resorption, space maintenance), alloplast (hydroxyapatite, beta-TCP).
- Membranes: non-resorbable ePTFE (space maintenance, requires removal, exposure risk) versus resorbable collagen (fewer visits, less support).
- Biologics: enamel matrix derivative (conditions the root surface, promotes acellular cementum), rhPDGF-BB, platelet concentrates; evidence is strongest for EMD in intrabony defects.
- Predictability: 3-wall intrabony > 2-wall > 1-wall; Class II furcation > Class III; Miller Class I–II recession > III–IV. Smoking, poor plaque control and membrane exposure reduce success.
- Root coverage: coronally advanced flap with connective tissue graft is the reference standard; the tunnel technique avoids releasing incisions.
Worked example
A mandibular molar has a 5 mm three-wall intrabony defect, PD 7 mm, no furcation, and the patient is a non-smoker with excellent hygiene. GTR plus graft (or EMD) is reasonable. If the same defect were one-wall, 8 mm deep with a Class III furcation, regeneration would be unpredictable and extraction with implant planning should be discussed.
Traps
Offering regeneration for horizontal bone loss; calling a Class III furcation a regenerative candidate; forgetting that EMD conditions rather than grafts the root; ignoring plaque control as the rate-limiting factor.