CIT Prosthetic Components & Restoration Flashcards

Which type of implant-supported prosthesis uses a metal bar connecting multiple implants to support a removable overdenture?

Answer: Bar-retained overdenture

A bar-retained overdenture uses a metal bar spanning multiple implants, with clips or attachments in the denture that snap onto the bar for retention.

When fabricating a zirconia implant crown, which factor is most critical to account for during milling to ensure accurate final fit?

Answer: Sintering shrinkage compensation (approximately 20-25%)

Zirconia must be milled oversized by approximately 20-25% to compensate for the shrinkage that occurs during the sintering process.

A patient has a single-unit implant crown with a 5 mm emergence profile. Which abutment height is most appropriate for a cement-retained restoration with 2 mm of soft tissue?

Answer: 2 mm abutment height

When soft tissue is 2 mm, a 2 mm abutment height ensures adequate cement retention while keeping the margin accessible for cement removal.

What is the primary purpose of a custom impression coping in implant prosthodontics?

Answer: To replicate the exact soft tissue contour around the implant in the final impression

Custom impression copings capture the unique gingival contours that have been shaped during the provisional restoration phase, ensuring the master cast replicates the actual peri-implant tissue architecture.

In an All-on-4 implant-supported prosthesis, the two posterior implants are typically angled at approximately how many degrees from vertical?

Answer: 30–45 degrees

Posterior implants in the All-on-4 concept are typically angled 30–45 degrees to maximize bone contact, avoid anatomical structures, and extend the posterior cantilever support.

Which retention mechanism in implant-supported overdentures requires the least amount of interocclusal space?

Answer: Magnetic attachment

Magnetic attachments require the least vertical space of all overdenture retention systems, making them suitable for patients with minimal interarch distance.

When torquing an abutment screw, which technique best ensures accurate final torque delivery?

Answer: Pre-torque to half value, wait 10 minutes, then apply final torque

Pre-torquing to half the recommended value, waiting 10 minutes to allow stress relaxation, and then applying final torque helps achieve accurate, stable seating of the abutment screw.