100+ Free RDA Practice Questions

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Question 1

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Pit and fissure sealants are most commonly placed on which tooth surface?

Lingual surfaces of anterior teeth

Occlusal surfaces of posterior teeth

Buccal surfaces of canines

Interproximal surfaces of incisors

to track

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Study Guides

AMT Registered Medical Assistant Study Guide

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2026 Statistics

Key Facts: RDA Exam

210

Total Items

AMT RDA

3 hrs

Exam Time

AMT

$135

Exam Fee

AMT

CPR

Required

BLS for Healthcare Provider

AMT RDA is the AMT national dental assistant credential (separate from CA state RDA). 210 items, 3 hours, $135. Requires HS + accredited program + current CPR. Master Universal tooth numbering #1-32, dental anatomy (32 permanent teeth), 4-handed assisting, ALARA radiation safety, intraoral imaging technique errors (cone cut, elongation, foreshortening, overlap), and medical emergency response.

Sample RDA Practice Questions

Try these sample questions to test your RDA exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In the Universal Numbering System, which tooth is designated as #1?

A.Maxillary right third molar

B.Maxillary left third molar

C.Mandibular right third molar

D.Mandibular left third molar

Explanation: The Universal Numbering System begins with #1 at the maxillary right third molar and proceeds clockwise (from the operator's view) across the maxillary arch to #16 at the maxillary left third molar, then continues at #17 (mandibular left third molar) to #32 (mandibular right third molar).

2How many teeth are in the complete permanent dentition?

A.20

B.28

C.32

D.24

Explanation: The complete permanent dentition contains 32 teeth: 8 incisors, 4 canines, 8 premolars, and 12 molars (including 4 third molars/wisdom teeth).

3Which dental tissue is the hardest substance in the human body?

A.Dentin

B.Enamel

C.Cementum

D.Pulp

Explanation: Enamel is the hardest substance in the human body. It is acellular (contains no living cells), composed of approximately 96% inorganic hydroxyapatite, and cannot regenerate once damaged.

4In the FDI two-digit notation system, which tooth is designated as 11?

A.Maxillary right central incisor

B.Maxillary left central incisor

C.Mandibular right central incisor

D.Mandibular left lateral incisor

Explanation: In FDI notation, the first digit represents the quadrant (1=upper right, 2=upper left, 3=lower left, 4=lower right) and the second digit represents the tooth position from midline. Tooth 11 is the maxillary right central incisor.

5How many teeth are in the complete primary dentition?

A.32

B.24

C.20

D.16

Explanation: The complete primary (deciduous) dentition consists of 20 teeth: 8 incisors, 4 canines, and 8 molars. There are no premolars in the primary dentition. Primary teeth are lettered A through T in the Universal system.

6At what age do the first permanent molars typically erupt?

A.3 years

B.6 years

C.12 years

D.18 years

Explanation: First permanent molars erupt at approximately age 6 and are commonly called 'six-year molars.' They erupt distal to the primary second molars without replacing any primary tooth.

7Which tooth surface faces the tongue on mandibular teeth?

A.Buccal

B.Facial

C.Lingual

D.Mesial

Explanation: The lingual surface faces the tongue on both maxillary and mandibular teeth. On maxillary teeth, the tongue-facing surface is sometimes called palatal because it faces the palate.

8Which local anesthetic is the most commonly used amide anesthetic in dentistry?

A.Procaine

B.Lidocaine

C.Benzocaine

D.Tetracaine

Explanation: Lidocaine is the most commonly used local anesthetic in dentistry. It is an amide-type anesthetic with rapid onset and a moderate duration of action, frequently combined with epinephrine 1:100,000 as a vasoconstrictor.

9What is the purpose of epinephrine added to local anesthetic at 1:100,000 concentration?

A.Increase pain perception

B.Vasoconstriction to prolong anesthesia and reduce bleeding

C.Vasodilation to speed onset

D.Antibacterial action

Explanation: Epinephrine acts as a vasoconstrictor, narrowing blood vessels at the injection site. This prolongs the duration of anesthesia, reduces systemic absorption of the anesthetic, and decreases bleeding in the surgical field.

10What is the standard temperature and time for steam autoclave sterilization?

A.100°C for 5 minutes

B.121°C (250°F) for 15-30 minutes

C.60°C for 60 minutes

D.200°C for 2 minutes

Explanation: A standard gravity-displacement steam autoclave operates at 121°C (250°F) and 15 psi for 15-30 minutes. This pressure-temperature combination kills all microorganisms including bacterial spores.

About the RDA Exam

AMT national dental assistant credential — distinct from California state-licensed RDA. Covers office assisting (scheduling, recordkeeping, insurance, communication), dental sciences (anatomy/Universal numbering, histology, embryology, pharmacology, infection control, microbiology), clinical procedures (4-handed assisting, instruments, restorative, endo, perio, prostho, ortho, oral surgery), and dental imaging (BWX/PA/Pano/CBCT, technique errors, ALARA, processing).

Questions

210 scored questions

Time Limit

3 hours

Passing Score

Scaled (AMT-set)

Exam Fee

$135 (AMT)

RDA Exam Content Outline

33.3%

Dental Sciences

Tooth numbering (Universal #1-32, FDI), dentition, histology, embryology, pharmacology, infection control, microbiology

29.0%

Clinical Procedures

4-handed assisting, instruments, cavity classes, restorative, endo, perio, prostho, ortho, oral surgery, vital signs

24.3%

Dental Imaging

BWX/PA/Pano/CBCT, ALARA, lead apron, paralleling vs bisecting, technique errors, PSP/digital

13.3%

Office Assisting

Scheduling, recordkeeping, insurance, reception, HIPAA, communication, billing

0.1%

Medical Emergency Response

Syncope (Trendelenburg), anaphylaxis (epi 0.3 mg IM), hypoglycemia, MI (MONA), seizure

How to Pass the RDA Exam

What You Need to Know

Passing score: Scaled (AMT-set)
Exam length: 210 questions
Time limit: 3 hours
Exam fee: $135

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

RDA Study Tips from Top Performers

1Master Universal tooth numbering (#1 max R 3rd molar → #16 max L → #17 mand L → #32 mand R)

2Memorize 32 permanent teeth: 8 incisors + 4 canines + 8 premolars + 12 molars (incl. wisdom)

3Drill radiograph technique errors: cone cut (PID), elongation (vertical low), foreshortening (vertical high), overlap (horizontal)

4Apply ALARA: lead apron + thyroid collar + fastest receptor + rectangular collimation + 6 ft / 90-135°

5Know dental medical emergencies: syncope (Trendelenburg), anaphylaxis (epi 0.3 mg IM), hypoglycemia (oral glucose if conscious), MI (MONA + 911)

Frequently Asked Questions

What is the Universal tooth numbering system?

Universal Numbering System (most common in US): #1 = maxillary RIGHT 3rd molar; numbers continue across upper arch to #16 = maxillary LEFT 3rd molar; #17 = mandibular LEFT 3rd molar; continues across lower arch to #32 = mandibular RIGHT 3rd molar. Primary teeth use letters A-T (A = max R 2nd primary molar; T = mand R 2nd primary molar). FDI uses two-digit format: quadrant + tooth (e.g., #11 = max R central incisor).

How do you correct cone-cut radiograph errors?

Cone cut (PID/aiming ring not aligned with receptor) appears as a clear/unexposed area on the film. Correction: re-aim PID so the central beam is fully aligned with the receptor (use a beam alignment device — XCP, RINN). Other common errors: elongation (insufficient vertical angulation — image stretched), foreshortening (excessive vertical angulation — image compressed), overlap (incorrect horizontal angulation — proximal contacts overlap).

What ALARA precautions apply to dental radiography?

ALARA = As Low As Reasonably Achievable. Use: lead apron + thyroid collar on every patient; fastest available receptor (digital sensors require ~50% less dose than F-speed film); rectangular collimation reduces exposure 60% vs round; long PID (16") reduces beam divergence; operator stands 6 ft away or behind shielding at 90-135° from beam direction; never hand-hold film (use receptor holders); pregnant patients — postpone non-essential, but emergency films safe with shielding.

How should I study for AMT RDA?

Plan 60-100 hours over 8-12 weeks. AMT RDA weighting heavily favors Dental Sciences (33.3%) and Clinical Procedures (29.0%). Master Universal tooth numbering, the 32-tooth permanent dentition, common cavity classes (I-VI by Black), instrument identification (mirror/explorer/probe/scaler/curette), 4-handed transfer, and radiograph technique errors. Maintain current BLS CPR — required for application.