RDA Dental Specialties Assisting (Orthodontics, Periodontics, Oral Surgery, Endodontics, and Prosthodontics)

Question 1

During an orthodontic appointment, a dental assistant uses a scaler to remove excess bonding material around a newly placed bracket. This instrument technique is called:

Accepted Answer

Flash removal

Answer

After brackets are bonded to teeth, excess adhesive ('flash') that squeezes out from under the bracket base must be removed before the bonding agent is light-cured or while it is still pliable. This process is called flash removal and is a routine expanded duty in orthodontic assisting.

Question 2

In periodontal surgery, a periosteal elevator is used to:

Accepted Answer

Reflect and retract the mucoperiosteal flap away from the bone

Answer

A periosteal elevator (e.g., Molt #9) is designed to separate and reflect the mucoperiosteal flap—the combined periosteum and overlying gingiva—from the underlying alveolar bone during flap surgery. This provides access for osseous reshaping or grafting procedures.

Question 3

Which instrument is used during a tooth extraction to loosen the periodontal ligament fibers and expand the alveolar socket before forceps are applied?

Accepted Answer

Elevator

Answer

Elevators (e.g., straight elevator, Cryer elevator) are placed between the tooth and the socket wall to sever periodontal ligament fibers and expand (luxate) the alveolus, making forceps delivery easier and safer. Rongeurs trim bone after extraction; curettes are periodontal instruments.

Question 4

During root canal therapy, a rubber dam is placed primarily to:

Accepted Answer

Isolate the field and prevent contamination of the canal with oral bacteria

Answer

The rubber dam isolates the tooth being treated, keeping saliva and oral bacteria out of the root canal system. Endodontic success depends on achieving and maintaining asepsis throughout the procedure. The rubber dam is considered mandatory for safe endodontic treatment.

Question 5

A final impression for a full-coverage crown is most commonly taken using a:

Accepted Answer

Polyvinyl siloxane (PVS) in a custom or triple tray

Answer

Polyvinyl siloxane (PVS), also called vinyl polysiloxane, is the standard material for final (definitive) crown and bridge impressions due to its dimensional accuracy, elastic recovery, and tear resistance. Alginate is used for study models and opposing arch impressions, not final prosthetic impressions.

(RDA) Registered Dental Assistant Practice Test

(RDA) Registered Dental Assistant Practice Test

RDA Dental Specialties Assisting (Orthodontics, Periodontics, Oral Surgery, Endodontics, and Prosthodontics)