CCA Implant-Retained Prosthetics 2 — Questions and Answers
Question 1: Which retention system uses a milled bar connected between two or more implants over which a corresponding clip on the prosthesis engages?
- Magnet retention
- Bar-clip retention (Correct answer)
- Ball attachment retention
- Stud abutment retention
Correct answer: Bar-clip retention
Bar-clip retention uses a custom-milled bar spanning multiple implants with a matching clip housed in the prosthesis for secure attachment.
Question 2: When planning implant placement for an auricular prosthesis, which anatomical landmark is most critical to avoid?
- Temporal line
- Mastoid air cells (Correct answer)
- Zygomatic arch
- Tragal cartilage
Correct answer: Mastoid air cells
Mastoid air cells must be avoided during auricular implant placement to prevent communication with the middle ear and risk of infection.
Question 3: What is the recommended minimum bone volume at a craniofacial implant site to ensure osseointegration?
- 2–3 mm depth
- 3–4 mm depth
- 4–5 mm depth (Correct answer)
- 6–8 mm depth
Correct answer: 4–5 mm depth
A minimum bone depth of approximately 4–5 mm is generally required for adequate craniofacial implant osseointegration and stability.
Question 4: Which magnetic retention component is housed within the prosthesis and attracted to a corresponding keeper on the abutment?
- Keeper magnet
- Rare-earth magnet cassette (Correct answer)
- Hader bar
- Locator cap
Correct answer: Rare-earth magnet cassette
The rare-earth magnet cassette is embedded in the prosthesis and attracted to a ferromagnetic keeper seated on the implant abutment.
Question 5: A patient presents with hypergranulation tissue at the percutaneous implant site. What is the FIRST recommended management step?
- Immediate implant removal
- Topical corticosteroid application
- Increased cleaning frequency with chlorhexidine (Correct answer)
- Surgical debridement under general anesthesia
Correct answer: Increased cleaning frequency with chlorhexidine
Hypergranulation at the skin-implant interface is initially managed by intensifying hygiene with chlorhexidine before considering more invasive interventions.
Question 6: In osseointegration theory originally described by Brånemark, what is the direct structural and functional connection between bone and implant surface?
- Fibro-osseous integration
- Osseointegration (Correct answer)
- Pseudoperiosteum formation
- Connective tissue encapsulation
Correct answer: Osseointegration
Osseointegration is the direct, load-bearing contact between living bone and a titanium implant surface without intervening connective tissue.
Question 7: Which factor most significantly increases the risk of implant failure in craniofacial sites compared to dental implant sites?
- Thinner cortical bone with less cancellous support (Correct answer)
- Higher oral bacterial load
- Absence of periosteum in the skull
- Greater occlusal loading forces
Correct answer: Thinner cortical bone with less cancellous support
Craniofacial bone is often thin with minimal cancellous support, limiting implant engagement depth and increasing failure risk compared to jaw bone.
