ABP Regenerative Techniques 2 — Questions and Answers
Question 1: Which growth factor found in platelet-rich plasma (PRP) is primarily responsible for stimulating angiogenesis during periodontal regeneration?
- PDGF-BB
- VEGF (Correct answer)
- TGF-β1
- IGF-1
Correct answer: VEGF
VEGF (vascular endothelial growth factor) is the primary angiogenic growth factor in PRP that promotes new blood vessel formation essential for tissue regeneration.
Question 2: When using enamel matrix derivative (EMD) in periodontal regeneration, the protein primarily responsible for its regenerative effect is:
- Ameloblastin
- Amelogenin (Correct answer)
- Enamelin
- Tuftelin
Correct answer: Amelogenin
Amelogenin constitutes approximately 90% of EMD proteins and is considered the primary active component responsible for cementum formation and periodontal regeneration.
Question 3: A critical factor distinguishing a space-maintaining membrane from one that does not require space maintenance in GTR is:
- Membrane porosity
- Membrane rigidity or stiffness (Correct answer)
- Membrane color
- Membrane thickness only
Correct answer: Membrane rigidity or stiffness
Membrane rigidity or stiffness is the critical property that allows a membrane to resist soft tissue collapse and maintain space for regeneration without requiring additional support.
Question 4: In the biology of periodontal regeneration, which cell type from the periodontal ligament is considered the most important progenitor for new cementum formation?
- Osteoblasts migrating from alveolar bone
- PDL fibroblasts near the cementum surface (Correct answer)
- Epithelial rest cells of Malassez
- Gingival fibroblasts
Correct answer: PDL fibroblasts near the cementum surface
PDL fibroblasts adjacent to the cementum surface are the key progenitor cells that differentiate into cementoblasts and produce new cementum during regeneration.
Question 5: Which type of bone defect has the WORST prognosis for regenerative therapy?
- Three-wall intrabony defect
- Two-wall intrabony defect
- One-wall intrabony defect (Correct answer)
- Combination defect with furcation involvement
Correct answer: One-wall intrabony defect
One-wall intrabony defects provide the least osseous support and blood supply for regeneration, resulting in the poorest regenerative outcomes compared to multi-wall defects.
Question 6: The 'coronal gain' measured in clinical trials of regenerative procedures primarily reflects changes in:
- Alveolar bone height only
- Clinical attachment level (Correct answer)
- Probing pocket depth only
- Gingival margin position
Correct answer: Clinical attachment level
Coronal gain in regenerative trials is measured by clinical attachment level (CAL) change, which accounts for both pocket depth reduction and changes in gingival margin position.
Question 7: Which surgical access design is MOST recommended when placing a barrier membrane in a narrow, deep intrabony defect to minimize membrane exposure?
- Conventional full-thickness mucoperiosteal flap with releasing incisions
- Papilla preservation flap (modified or simplified) (Correct answer)
- Envelope flap without vertical releases
- Apically repositioned flap
Correct answer: Papilla preservation flap (modified or simplified)
Papilla preservation flaps (Cortellini's MPPT or SPPF) minimize tension at the interdental closure site, significantly reducing the risk of membrane exposure in narrow interproximal defects.
ABP Regenerative Techniques 2
Which growth factor found in platelet-rich plasma (PRP) is primarily responsible for stimulating angiogenesis during periodontal regeneration?