CIT CIT Bone Grafting & Osseointegration 4 — Questions and Answers
Question 1: Which growth factor found in platelet-rich plasma (PRP) is most directly responsible for stimulating osteoblast proliferation at a graft site?
- PDGF (Platelet-Derived Growth Factor) (Correct answer)
- TNF-alpha
- IL-6
- MMP-9
Correct answer: PDGF (Platelet-Derived Growth Factor)
PDGF is the primary mitogen in PRP that directly stimulates osteoblast proliferation and recruitment to the graft site.
Question 2: A patient presents with a severely atrophic maxilla requiring vertical bone augmentation. Which technique is most appropriate for gaining more than 5 mm of vertical height?
- Distraction osteogenesis (Correct answer)
- Guided bone regeneration with a membrane alone
- Socket preservation with DFDBA
- Sinus floor elevation via the crestal approach
Correct answer: Distraction osteogenesis
Distraction osteogenesis can achieve vertical gains exceeding 5 mm by slowly separating bone segments to stimulate new bone formation in the distraction gap.
Question 3: What is the primary advantage of using a cross-linked collagen membrane over a non-cross-linked one in GBR procedures?
- Prolonged resorption time allowing longer barrier function (Correct answer)
- Greater initial tensile strength at placement
- Enhanced angiogenesis beneath the membrane
- Reduced risk of membrane exposure causing infection
Correct answer: Prolonged resorption time allowing longer barrier function
Cross-linking extends the collagen membrane's resorption time, maintaining the barrier function longer during the critical bone maturation phase.
Question 4: During sinus lift surgery, the Schneiderian membrane is perforated. Which of the following is the BEST immediate management strategy?
- Repair with a collagen membrane patch and continue the procedure if perforation is small (Correct answer)
- Abort the procedure immediately and reschedule in 6 months
- Pack the sinus with iodoform gauze and close
- Place the implant immediately without grafting
Correct answer: Repair with a collagen membrane patch and continue the procedure if perforation is small
Small perforations can be managed with a resorbable collagen membrane patch that acts as a scaffold, allowing the procedure to continue safely.
Question 5: In the context of implant osseointegration, what does the Implant Stability Quotient (ISQ) measure?
- Resonance frequency of the implant-bone interface via an electromagnetic transducer (Correct answer)
- Torque required to remove the implant at uncovery
- Bone-to-implant contact percentage via histomorphometry
- Radiographic density of peri-implant bone
Correct answer: Resonance frequency of the implant-bone interface via an electromagnetic transducer
ISQ uses resonance frequency analysis (RFA) to quantify implant stability non-invasively on a scale of 1–100.
Question 6: Which of the following systemic medications is most likely to impair osseointegration by reducing osteoclast-mediated bone remodeling?
- Bisphosphonates (Correct answer)
- Metformin
- Atorvastatin
- Amlodipine
Correct answer: Bisphosphonates
Bisphosphonates suppress osteoclast activity, which can impair the normal bone remodeling essential for osseointegration and carries a risk of MRONJ.
Question 7: A block graft harvested from the mandibular ramus is classified as which type of bone graft?
- Autograft (Correct answer)
- Allograft
- Xenograft
- Alloplast
Correct answer: Autograft
An autograft is bone harvested from the patient's own body, making ramus block grafts the gold standard for osteogenic potential.
CIT CIT Bone Grafting & Osseointegration 4
Which growth factor found in platelet-rich plasma (PRP) is most directly responsible for stimulating osteoblast proliferation at a graft site?