CDT Orthodontic Appliance Construction 3

Question 1

Which material is used to invest wire components before processing acrylic for a removable appliance to protect them from displacement?

Accepted Answer

Sticky wax and baseplate wax

Answer

Sticky wax and baseplate wax are used to secure wire components to the model in their correct positions so they remain stable when the acrylic dough is applied.

Question 2

A lower lingual arch space maintainer is soldered to which tooth type to maintain arch length after premature primary tooth loss?

Accepted Answer

Mandibular first or second permanent molars

Answer

The lower lingual arch is soldered to bands on the mandibular first or second permanent molars, which serve as stable anchor teeth to prevent mesial drift.

Question 3

When constructing a Nance palatal arch, the acrylic button is placed to contact which anatomical area?

Accepted Answer

The rugae area of the anterior hard palate

Answer

The Nance button rests on the rugae of the anterior hard palate, using tissue contact as anchorage to resist mesial movement of the upper molars.

Question 4

What is the gauge range most commonly used for stainless steel wire when fabricating the labial bow of a Hawley retainer?

Accepted Answer

0.5–0.6 mm (22–24 gauge)

Answer

The labial bow of a Hawley retainer is typically constructed from 0.5–0.6 mm (22–24 gauge) stainless steel wire, balancing flexibility for passive retention with sufficient rigidity.

Question 5

Which finishing step is essential before delivering a removable orthodontic appliance to the clinician to prevent soft tissue irritation?

Accepted Answer

Polishing with pumice and rag wheel to a smooth, glossy finish

Answer

Polishing the acrylic with pumice followed by a high-gloss polish removes surface scratches that would harbor bacteria and irritate the mucosal tissues.

(CDT) Certified Dental Technicians Practice Test

(CDT) Certified Dental Technicians Practice Test

CDT Orthodontic Appliance Construction 3