NDAEB Clinical Support Procedures Questions and Answers

Question 1

A dentist is preparing to permanently cement a porcelain crown and asks the assistant to mix a glass ionomer luting cement. For optimal luting consistency, how should the cement appear when properly mixed?

Accepted Answer

Creamy and glossy, stretching about one inch from the mixing pad before breaking

Answer

Luting cements require a specific viscosity to flow adequately and create a strong, thin film layer for permanent cementation. A creamy consistency that strings up about one inch indicates the correct powder-to-liquid ratio. A putty-like consistency is used for a base, while a dry or watery mix would compromise the cement's physical properties and lead to failure.

Question 2

In four-handed dentistry, which of the following describes the most efficient and safe method for a dental assistant to transfer a sharp instrument, such as an explorer, to a right-handed operator?

Accepted Answer

Holding the instrument parallel to the instrument in the operator's hand and transferring it near the patient's chin.

Answer

The correct technique involves holding the new instrument at the end opposite the working end, parallel to the one being returned. The exchange occurs in the 'transfer zone' below the patient's chin and over the patient's chest to maintain efficiency and avoid passing instruments over the patient's face, ensuring both ergonomic safety and smooth workflow.

Question 3

During a morning appointment, a patient with a known history of Type 1 diabetes suddenly becomes agitated, confused, and their skin feels cold and clammy. They have not yet had their lunch. These signs are most indicative of which medical emergency?

Accepted Answer

Hypoglycemia

Answer

The rapid onset of confusion, agitation, and cold, clammy skin in a diabetic patient who has likely taken insulin but not eaten is characteristic of hypoglycemia (low blood sugar). The immediate response is to administer a source of sugar if the patient is conscious. Hyperglycemia typically has a slower onset, while anaphylaxis and syncope present with different primary symptoms.

Question 4

After taking an alginate impression, it is disinfected. To prevent dimensional distortion due to syneresis or imbibition, what is the ideal timeframe for pouring the gypsum model?

Accepted Answer

As soon as possible, ideally within one hour.

Answer

Alginate is a hydrocolloid material that is dimensionally unstable due to its high water content. It loses water and shrinks (syneresis) or absorbs water and expands (imbibition). To ensure the most accurate model, the impression must be poured with gypsum stone as soon as reasonably possible, with a one-hour timeframe being the generally accepted maximum to minimize distortion.

Question 5

A dental assistant is assisting with the placement of a dental dam. After the dam is placed, the operator uses an instrument to tuck the edges of the dam material into the gingival sulcus around each isolated tooth. What is the primary purpose of this 'inverting' step?

Accepted Answer

To create a complete seal around the teeth and prevent moisture leakage from the sulcus.

Answer

Inverting the dental dam creates a tight seal that prevents saliva and sulcular fluid from seeping onto the isolated operating field. This moisture control is critical for the success of adhesive dental procedures, such as composite restorations and sealants, by ensuring a clean, dry surface for bonding.

(NDAEB) National Dental Assisting Examination Board Practice Test

(NDAEB) National Dental Assisting Examination Board Practice Test

NDAEB Clinical Support Procedures Questions and Answers