Dental Implants Bone Grafting & Ridge Augmentation 2 — Questions and Answers
Question 1: Which term describes the property of a graft material that provides a scaffold along which host bone cells can migrate and form new bone?
- Osteogenesis
- Osteoconduction (Correct answer)
- Osteoinduction
- Osseointegration
Correct answer: Osteoconduction
Osteoconduction refers to the scaffold property of graft material that provides a physical framework for host osteoblasts and vascular tissue to migrate into and form new bone along its surface.
Question 2: Which process best describes osteoinduction in bone grafting?
- Physical scaffold provided for osteoblast attachment
- Direct bone formation from transplanted living osteoblasts
- Stimulation of undifferentiated mesenchymal cells to become bone-forming cells (Correct answer)
- Remodeling of mature lamellar bone after graft placement
Correct answer: Stimulation of undifferentiated mesenchymal cells to become bone-forming cells
Osteoinduction is the process by which signaling molecules (particularly BMPs) stimulate undifferentiated mesenchymal stem cells to differentiate into osteoblasts, initiating de novo bone formation in non-osseous tissue.
Question 3: Which growth factor, found in demineralized bone matrix, plays the most critical role in bone regeneration by stimulating osteoblast differentiation?
- Vascular endothelial growth factor (VEGF)
- Bone morphogenetic protein (BMP) (Correct answer)
- Epidermal growth factor (EGF)
- Fibroblast growth factor (FGF)
Correct answer: Bone morphogenetic protein (BMP)
Bone morphogenetic proteins (BMPs), particularly BMP-2 and BMP-7, are the most potent osteoinductive signals; they are exposed during demineralization of bone matrix and are FDA-approved as recombinant proteins for bone regeneration.
Question 4: What is the primary goal of socket preservation (ridge preservation) performed immediately after tooth extraction?
- To immediately place and stabilize a dental implant
- To minimize alveolar bone resorption following extraction (Correct answer)
- To treat pre-existing peri-apical infection at the extraction site
- To increase the width of keratinized gingival tissue
Correct answer: To minimize alveolar bone resorption following extraction
Socket preservation using bone graft material placed immediately after extraction significantly reduces the natural dimensional changes (up to 50% width reduction) that occur in the alveolar ridge during the first 3-6 months post-extraction.
Question 5: Which type of GBR membrane requires a planned second surgical procedure for removal?
- Collagen membrane
- Polylactic acid membrane
- Polyglycolic acid membrane
- Expanded polytetrafluoroethylene (e-PTFE) membrane (Correct answer)
Correct answer: Expanded polytetrafluoroethylene (e-PTFE) membrane
Non-resorbable e-PTFE (Gore-Tex) membranes provide superior space maintenance but must be surgically retrieved in a second procedure; collagen, polylactic acid, and polyglycolic acid membranes are all bioresorbable and degrade without additional surgery.
Question 6: What is the primary indication for the ridge splitting (ridge expansion) technique in implant dentistry?
- Treating active peri-implantitis around existing implants
- Widening a narrow but adequately tall alveolar ridge to accommodate an implant (Correct answer)
- Increasing vertical bone height in the atrophic posterior maxilla
- Creating soft tissue volume for aesthetic implant emergence profiles
Correct answer: Widening a narrow but adequately tall alveolar ridge to accommodate an implant
Ridge splitting uses chisels or piezoelectric devices to create a greenstick fracture in a narrow ridge, expanding the cortical plates to create width for simultaneous implant placement and bone grafting while maintaining the native ridge height.
Question 7: What is the primary benefit of incorporating platelet-rich fibrin (PRF) or platelet-rich plasma (PRP) into bone grafting procedures?
- It permanently replaces the need for barrier membranes in GBR
- It provides a long-lasting osteoconductive scaffold for bone formation
- It concentrates autologous growth factors that may accelerate tissue healing (Correct answer)
- It eliminates the need for bone graft particulate material entirely
Correct answer: It concentrates autologous growth factors that may accelerate tissue healing
PRF and PRP are prepared from the patient's own blood and concentrate growth factors such as PDGF, TGF-β, and VEGF; when used as adjuncts in grafting procedures, they may promote angiogenesis and accelerate graft healing and maturation.
Dental Implants Bone Grafting & Ridge Augmentation 2
Which term describes the property of a graft material that provides a scaffold along which host bone cells can migrate and form new bone?