Dental Implants Osseointegration & Healing 2 — Questions and Answers
Question 1: The 'stability dip' phenomenon during implant healing occurs because:
- The implant loosens due to infection
- Primary stability decreases before secondary stability fully develops during remodeling (Correct answer)
- The crown is placed too early
- Bone grafts resorb before the implant integrates
Correct answer: Primary stability decreases before secondary stability fully develops during remodeling
During early healing, bone remodeling reduces the initial mechanical grip (primary stability) before new bone formation (secondary stability) compensates — creating a temporary dip.
Question 2: Growth factors contained in platelet-rich fibrin (PRF) that enhance implant site healing include:
- TNF-alpha and IL-6
- PDGF, TGF-beta, and VEGF (Correct answer)
- Cortisol and epinephrine
- Histamine and bradykinin
Correct answer: PDGF, TGF-beta, and VEGF
PRF releases platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-β), and vascular endothelial growth factor (VEGF) to accelerate healing and angiogenesis.
Question 3: Fibro-osseous integration (as opposed to osseointegration) is considered a failure because:
- It is too rigid and causes bone fractures
- A fibrous tissue layer at the interface lacks mechanical stability and is prone to breakdown (Correct answer)
- It causes excessive bone growth around the implant
- The implant fuses permanently and cannot be removed
Correct answer: A fibrous tissue layer at the interface lacks mechanical stability and is prone to breakdown
Fibrous encapsulation creates a weak, mobile interface similar to a non-union fracture — the implant may feel firm initially but typically fails under functional loading.
Question 4: The peri-implant blood clot formed immediately after implant placement serves as:
- A barrier to prevent infection only
- A scaffold for cellular migration and initiating the healing cascade (Correct answer)
- Permanent connective tissue
- A substitute for bone graft material
Correct answer: A scaffold for cellular migration and initiating the healing cascade
The fibrin clot matrix provides a provisional scaffold for cell migration including osteoblasts, fibroblasts, and endothelial cells that initiate tissue regeneration.
Question 5: Which systemic condition most severely impairs osseointegration by reducing osteoblast function?
- Controlled hypertension
- Osteoporosis (Correct answer)
- Well-managed hypothyroidism
- Controlled asthma
Correct answer: Osteoporosis
Osteoporosis reduces bone density and osteoblast activity, potentially compromising bone-to-implant contact and increasing fracture risk around implants.
Question 6: Stress shielding around dental implants refers to:
- Protective effect of implants on adjacent teeth
- Reduced bone stimulation in areas shielded from occlusal load, leading to bone resorption (Correct answer)
- The implant preventing occlusal forces from reaching the sinus
- Cortical bone protecting the implant from micromovement
Correct answer: Reduced bone stimulation in areas shielded from occlusal load, leading to bone resorption
Areas of bone not receiving adequate functional stimulation due to the stiffness of the implant (stress shielding) undergo disuse atrophy and resorption.
Dental Implants Osseointegration & Healing 2
The 'stability dip' phenomenon during implant healing occurs because: