Implant-Retained Prosthetics Flashcards

For an orbital prosthesis retained by implants, which is the typical minimum number of implants placed to provide adequate multi-point retention?

Answer: 3

Three implants are typically placed for orbital prostheses to distribute retention forces and provide stable multi-point attachment.

What surface treatment on modern craniofacial titanium implants enhances osseointegration by increasing surface roughness?

Answer: Acid-etching or sandblasting (SLA surface)

Sandblasted, large-grit, acid-etched (SLA) surfaces increase microroughness, promoting bone cell attachment and accelerating osseointegration.

During abutment connection to an osseointegrated craniofacial implant, why is a torque-controlled wrench used?

Answer: To avoid stripping the abutment screw and over-compressing peri-implant bone

A calibrated torque wrench prevents abutment screw stripping and protects peri-implant bone from excessive compressive stress during tightening.

Which imaging modality is MOST appropriate for pre-surgical assessment of bone volume and architecture at a proposed nasal implant site?

Answer: Cone-beam computed tomography (CBCT)

CBCT provides three-dimensional visualization of bone volume, thickness, and proximity to critical structures at craniofacial implant sites.

A silicone auricular prosthesis retained by implants shows lateral displacement during mastication. What is the MOST likely cause?

Answer: Insufficient number of retention points or bar rigidity

Lateral displacement during function indicates inadequate retention stability, often due to too few implants or a flexible retention system unable to resist lateral forces.

What is the primary purpose of a healing abutment (cover screw stage) placed immediately after craniofacial implant surgery?

Answer: To protect the implant and shape the peri-implant skin during osseointegration

Healing abutments protect the implant from contamination and help condition the peri-implant skin to the correct profile during the osseointegration period.

Radiation therapy to the head and neck prior to craniofacial implant placement is a significant risk factor primarily because it causes:

Answer: Hypovascular, hypocellular, hypoxic bone (osteoradionecrosis risk)

Radiation damages the vasculature and cellular elements of bone, producing a hypoxic-hypovascular-hypocellular environment that impairs osseointegration and raises osteoradionecrosis risk.