Prometric Exam Questions for Dental Assistants and Dental Hygienists 2026: 15 Practice MCQs with Answers and Rationale

Dental assistants (DAS5111) and dental hygienists (DEN5141) sit separate Prometric papers, but they share most of the blueprint: infection control, dental anatomy, radiography, materials, chairside procedures and emergencies. Hygienists get more periodontal assessment and preventive therapy; assistants get more instrument and materials handling. Both papers are usually 100 to 150 single-best-answer questions in 2 to 3 hours, with pass marks around 55 to 60%.

The fifteen questions below cover the shared core plus a few from each side. Allow about 70 seconds each and read every rationale.

For eligibility, titles and the full syllabus, read the dental hygienist and dental assistant guide. For timed papers use the Dental Assistant bank or the Dental Hygienist bank.

Infection control and sterilisation

Question 1

The standard steam autoclave cycle for wrapped dental instruments is approximately:

1. 100 °C for 5 minutes
2. 121 °C for 15 to 20 minutes, or 134 °C for about 3 to 4 minutes
3. 60 °C for 60 minutes
4. 180 °C for 1 minute

Answer: B. Both cycles are standard; the 134 °C cycle is faster and common in dental practice. Each load is checked with chemical indicators, and biological indicators are run at set intervals.

Question 2

Before sterilisation, instruments must first be:

1. Dried only
2. Cleaned to remove debris, by ultrasonic cleaner or washer-disinfector, then rinsed and dried
3. Soaked in alcohol
4. Wrapped while still soiled

Answer: B. Sterilisation cannot penetrate dried blood or debris. Cleaning is the essential first step, done with heavy-duty gloves and eye protection.

Question 3

Which surface in the operatory should be covered with a barrier or disinfected between every patient?

1. The light handles, chair controls and headrest
2. Only the floor
3. The waiting-room chairs
4. Nothing, if gloves are worn

Answer: A. Clinical contact surfaces touched during treatment are barrier-covered or cleaned and disinfected with an approved intermediate-level disinfectant between patients.

Dental anatomy

Question 4

How many teeth are in the complete permanent dentition?

1. 20
2. 24
3. 28
4. 32

Answer: D. The permanent dentition has 32 teeth including third molars; the primary dentition has 20. In FDI notation the upper right permanent central incisor is 11 and the lower left first molar is 36.

Question 5

The first permanent tooth to erupt is usually the:

1. Upper central incisor
2. First molar, at about 6 years
3. Canine
4. Second premolar

Answer: B. The "six-year molar" erupts behind the primary molars without replacing any tooth, which is why parents often mistake it for a baby tooth and why fissure sealants are placed early.

Radiography

Question 6

Which radiograph best shows interproximal caries and the crestal bone level?

1. Panoramic
2. Bitewing
3. Occlusal
4. Lateral cephalogram

Answer: B. Bitewings show the crowns of upper and lower posterior teeth on one film, ideal for detecting caries between teeth and early bone loss. Periapicals show the whole tooth and apex.

Question 7

During an x-ray exposure, the operator should stand:

1. Next to the patient to hold the film
2. At least 2 metres away, outside the primary beam, or behind a barrier
3. In front of the tube head
4. Anywhere, as dental doses are tiny

Answer: B. Operators never hold the film or the tube head. Distance and shielding keep occupational dose as low as reasonably achievable, and a personal dosimeter is worn where required.

Materials and instruments

Question 8

Which impression material is most commonly used for crown and bridge impressions because of its accuracy and dimensional stability?

1. Alginate
2. Polyvinyl siloxane (addition silicone)
3. Impression compound
4. Zinc oxide eugenol paste

Answer: B. Addition silicones are accurate and stable, so they can be poured later. Alginate is for study models and must be poured within minutes because it loses water.

Question 9

Glass ionomer cement is valued in restorative dentistry mainly because it:

1. Is the strongest material available
2. Bonds chemically to tooth and releases fluoride
3. Needs no moisture control at all
4. Is used only for crowns

Answer: B. Fluoride release and chemical adhesion make it useful for cervical lesions, paediatric restorations, liners and luting. It is weaker than composite in load-bearing areas.

Question 10

During a restorative procedure, instruments are passed to the dentist in the:

1. Transfer zone, below the patient's chin, using a single-handed or two-handed transfer
2. Operator's zone, over the patient's face
3. Static zone, behind the patient
4. Assistant's zone, at the dentist's back

Answer: A. In four-handed dentistry the transfer zone is between 4 and 7 o'clock for a right-handed operator, keeping sharp instruments away from the patient's face.

Periodontal assessment and prevention

Question 11

A probing depth of 4 mm or more with bleeding on probing most suggests:

1. Healthy gingiva
2. Periodontal disease requiring further assessment and treatment
3. Normal variation
4. A cracked tooth

Answer: B. Healthy sulcus depth is 1 to 3 mm without bleeding. Deeper pockets with bleeding indicate inflammation and attachment loss, recorded on the periodontal chart with recession and mobility.

Question 12

The recommended fluoride concentration in toothpaste for most adults is:

1. 100 ppm
2. About 1,350 to 1,500 ppm
3. 10,000 ppm
4. Fluoride-free

Answer: B. Standard adult toothpaste contains 1,350 to 1,500 ppm fluoride; higher-strength 5,000 ppm pastes are prescribed for high-risk patients. Children under three use a smear of at least 1,000 ppm.

Question 13

Fissure sealants are placed on:

1. The smooth labial surfaces of incisors
2. The pits and fissures of newly erupted permanent molars
3. Root surfaces
4. Existing amalgam fillings

Answer: B. Sealants fill the deep fissures where plaque is hard to remove, ideally soon after eruption of the first and second permanent molars in children at risk of caries.

Medical emergencies in the dental chair

Question 14

A patient becomes pale, sweaty and light-headed during local anaesthetic injection. The most likely cause and first action are:

1. Anaphylaxis; give adrenaline at once
2. Vasovagal syncope; lay the patient flat with legs raised and monitor
3. Stroke; call an ambulance
4. Hypoglycaemia; give insulin

Answer: B. Fainting is the most common dental emergency. Position flat, raise the legs, loosen tight clothing, check airway and pulse, and reassure. If recovery is not quick, reassess for other causes.

Question 15

A known diabetic patient becomes confused and shaky mid-appointment and is still able to swallow. You should give:

1. A glucose drink, gel or sugar, then recheck
2. Insulin
3. Water only
4. Nothing until the doctor arrives

Answer: A. Treat suspected hypoglycaemia in a conscious patient with fast-acting oral glucose. If the patient cannot swallow or becomes unconscious, call for help and use glucagon or the emergency protocol.

How to use these questions

• Infection control is a third of the paper. Learn the cleaning, sterilisation and surface rules in order.
• Know FDI numbering and eruption dates cold.
• Hygienists: drill periodontal charting, instrumentation and fluoride regimes. Assistants: drill materials, mixing and instrument transfer.
• Practise under time in the Dental Assistant bank or Dental Hygienist bank.

Dentists sit the GEN5301 paper; see dentist sample questions. Dental lab staff have their own banks (dental lab technician guide). When you hold eligibility, join the dental talent pool.

Frequently asked questions

How many questions are in the dental assistant Prometric exam?

Usually 100 to 150 in 2 to 3 hours; the hygienist paper is similar. Your eligibility notice states the format.

What is the pass mark?

Around 55 to 60% depending on the title and authority.

Do dental assistants and hygienists sit the same exam?

No. DAS5111 is the assistant paper and DEN5141 the hygienist paper, with a shared core and different emphasis.

Which topics come up most?

Infection control and sterilisation, dental anatomy, radiography safety, materials and instruments, and medical emergencies.

Are these real exam questions?

No. They are original practice questions written to the published blueprint. Real exam content is confidential.