CDT Prosthodontic & Orthodontic Appliance Fabrication

Question 1

What is the purpose of a dental retainer?

Accepted Answer

To maintain alignment after braces

Answer

After orthodontic treatment with braces, teeth have a natural tendency to shift back towards their original positions, a phenomenon known as relapse. A dental retainer is an appliance, either removable or fixed, worn to hold the teeth in their newly corrected alignment. This stabilizes the surrounding bone and tissues, preserving the orthodontic results and maintaining the desired tooth position long-term.

Question 2

Which material is commonly used in denture bases?

Accepted Answer

Acrylic resin

Answer

Acrylic resin, specifically polymethyl methacrylate (PMMA), is the most commonly used material for fabricating denture bases. Its popularity stems from its excellent aesthetics, as it can be colored to closely match natural gum tissue, and its ease of processing. Acrylic resin is also biocompatible, relatively lightweight, and durable, providing a comfortable and functional foundation for artificial teeth.

Question 3

What is a common reason for relining a denture?

Accepted Answer

To improve fit due to tissue changes

Answer

Over time, the bone and soft tissues in a patient's mouth can resorb and change shape, causing a denture to become loose and ill-fitting. Relining involves adding new acrylic material to the tissue-fitting surface of the denture base to re-establish a snug and comfortable fit. This process improves the denture's retention and stability, enhancing comfort and function without requiring the fabrication of an entirely new denture.

Question 4

What is the main function of orthodontic brackets?

Accepted Answer

To support the archwire and guide teeth movement

Answer

Orthodontic brackets are small attachments bonded to the surface of teeth, serving as crucial anchors for the archwire. The archwire, which is threaded through these brackets, applies gentle, continuous forces that are transmitted to the teeth. This controlled force guides the teeth into their desired, corrected positions over time, facilitating effective orthodontic tooth movement.

Question 5

Which appliance is used to expand the upper jaw?

Accepted Answer

Palatal expander

Answer

A palatal expander is an orthodontic appliance specifically designed to gradually widen the upper jaw (maxilla) when it is too narrow. This is often necessary to correct a crossbite or create more space for crowded teeth. The expander works by applying gentle outward pressure to the two halves of the upper jaw, separating them at the midpalatal suture over a period of weeks or months.

(CDT) Certified Dental Technicians Practice Test

(CDT) Certified Dental Technicians Practice Test

CDT Prosthodontic & Orthodontic Appliance Fabrication