Periodontics · single question
Which of the following does NOT contribute to osteogenic (bone-forming) potential?
Show answer and explanation
Correct answer: C. Interleukin-1 (IL-1)
IL-1 is a pro-inflammatory cytokine that promotes bone resorption rather than formation, so it does not enhance osteogenic potential.Other options: TGF-beta, BMP, and IGF are growth factors that promote osteoblast activity and bone formation.Key exam takeaway: Growth factors (TGF-beta, BMP, IGF, PDGF) build bone; inflammatory cytokines like IL-1 and TNF favor resorption.
- A. PDGF promotes angiogenesis and mesenchymal cell proliferation and is used clinically in periodontal regeneration (rhPDGF-BB).
- B. BMPs (especially BMP-2 and BMP-7) are the prototypical OSTEOINDUCTIVE proteins — they induce mesenchymal stem cells to differentiate into osteoblasts. BMP-2 is FDA-approved for sinus augmentation and ridge preservation.
- C. CORRECT — this does NOT promote bone formation. IL-1 is a pro-inflammatory cytokine and one of the most potent stimulators of OSTEOCLASTIC bone RESORPTION. It upregulates RANKL, drives the bone destruction of periodontitis, and is a central mediator of inflammatory bone loss — the opposite of osteogenic potential.
- D. TGF-beta stimulates osteoblast proliferation and matrix synthesis and is a key regulator of bone remodeling.
Note: Osteoinduction: BMP, TGF-beta, PDGF, IGF. Resorption: IL-1, IL-6, TNF-alpha, PGE2, RANKL.