DANB CDA Certification Exam 2026: Comprehensive Certified Dental
Assistant Practice Test — General Chairside Assisting, Infection
Control, Radiation Health & Safety, Dental Materials & Patient Care
— 190 Multiple-Choice Questions with Answers & Detailed
Rationales
SECTION 1: GENERAL CHAIRSIDE ASSISTING (66 Questions)
Question 1
A patient presents for a composite restoration on tooth #14. During the procedure, the
dentist requests a matrix band and wedge. What is the primary purpose of the wedge in this
clinical scenario?
A. To protect the adjacent tooth from the matrix band
B. To compress the matrix band against the gingival margin and slightly separate the teeth
C. To hold the matrix band in place during curing
D. To provide a clear view of the proximal contact area
Correct Answer: B
Explanation: The wedge separates teeth slightly and presses the matrix band tightly against
the cervical margin, preventing overhang and restoring proper proximal contour.
Question 2
During a crown preparation appointment, the dentist asks you to mix glass ionomer cement
for cementation. What property of glass ionomer makes it particularly advantageous for this
application?
,A. High compressive strength comparable to amalgam
B. Fluoride release and chemical bonding to tooth structure
C. Rapid setting time under blue curing light
D. Superior esthetic translucency
Correct Answer: B
Explanation: Glass ionomer releases fluoride and chemically bonds to dentin and enamel,
providing both retention and caries-inhibiting benefits at the margin.
Question 3
A patient with a known latex allergy is scheduled for a prophylaxis. Which chairside
preparation is MOST critical to prevent an allergic reaction?
A. Rinsing the patient's mouth with an antihistamine solution
B. Replacing all latex-containing items with non-latex alternatives before seating
C. Pre-medicating the patient with epinephrine
D. Using only plastic instruments during treatment
Correct Answer: B
Explanation: Complete removal of latex products—gloves, dams, bands—is essential
because even minimal contact can trigger severe allergic responses in sensitized patients.
Question 4
During a surgical extraction, the dentist requests a periosteal elevator. What is the function
of this instrument?
,A. To remove bone surrounding the tooth
B. To reflect the gingival tissue and periosteum from bone
C. To luxate the tooth from the socket
D. To suture the extraction site closed
Correct Answer: B
Explanation: A periosteal elevator separates soft tissue from bone, creating a clean surgical
field and protecting underlying structures during extraction procedures.
Question 5
A patient reports taking warfarin (Coumadin) during the medical history review. The dentist
is planning a tooth extraction. What is the MOST appropriate chairside action?
A. Proceed with the extraction as planned since warfarin only affects cardiac function
B. Alert the dentist immediately because anticoagulant therapy increases bleeding risk
C. Ask the patient to stop taking warfarin for one week before the procedure
D. Document the medication and schedule the extraction for the next day
Correct Answer: B
Explanation: Anticoagulants significantly increase hemorrhage risk during invasive
procedures; the dentist must assess INR levels and may consult the physician before
proceeding.
Question 6
, When transferring a hinged instrument such as a forceps to the dentist, which technique is
correct?
A. Place the handles directly into the dentist's palm with the hinge oriented toward you
B. Transfer with the working end pointing toward the patient
C. Orient the hinge so the dentist's fingers grasp the handles in a ready-to-use position
D. Set the instrument on the tray for the dentist to retrieve independently
Correct Answer: C
Explanation: Hinged instruments require transfer with handles accessible and hinge
positioned so the dentist can immediately engage the patient without repositioning.
Question 7
A patient scheduled for amalgam restoration on tooth #30 has a history of epilepsy. During
the procedure, the patient begins to experience a seizure. What is the FIRST priority action?
A. Place a bite block to keep the mouth open and continue the procedure
B. Clear the oral cavity of instruments and materials, then protect the patient from injury
C. Administer oxygen via nasal cannula immediately
D. Restrain the patient's limbs to prevent injury
Correct Answer: B
Explanation: During a seizure, removing oral foreign bodies prevents aspiration, and
protecting the patient from physical injury is the immediate priority before medical
management.
Assistant Practice Test — General Chairside Assisting, Infection
Control, Radiation Health & Safety, Dental Materials & Patient Care
— 190 Multiple-Choice Questions with Answers & Detailed
Rationales
SECTION 1: GENERAL CHAIRSIDE ASSISTING (66 Questions)
Question 1
A patient presents for a composite restoration on tooth #14. During the procedure, the
dentist requests a matrix band and wedge. What is the primary purpose of the wedge in this
clinical scenario?
A. To protect the adjacent tooth from the matrix band
B. To compress the matrix band against the gingival margin and slightly separate the teeth
C. To hold the matrix band in place during curing
D. To provide a clear view of the proximal contact area
Correct Answer: B
Explanation: The wedge separates teeth slightly and presses the matrix band tightly against
the cervical margin, preventing overhang and restoring proper proximal contour.
Question 2
During a crown preparation appointment, the dentist asks you to mix glass ionomer cement
for cementation. What property of glass ionomer makes it particularly advantageous for this
application?
,A. High compressive strength comparable to amalgam
B. Fluoride release and chemical bonding to tooth structure
C. Rapid setting time under blue curing light
D. Superior esthetic translucency
Correct Answer: B
Explanation: Glass ionomer releases fluoride and chemically bonds to dentin and enamel,
providing both retention and caries-inhibiting benefits at the margin.
Question 3
A patient with a known latex allergy is scheduled for a prophylaxis. Which chairside
preparation is MOST critical to prevent an allergic reaction?
A. Rinsing the patient's mouth with an antihistamine solution
B. Replacing all latex-containing items with non-latex alternatives before seating
C. Pre-medicating the patient with epinephrine
D. Using only plastic instruments during treatment
Correct Answer: B
Explanation: Complete removal of latex products—gloves, dams, bands—is essential
because even minimal contact can trigger severe allergic responses in sensitized patients.
Question 4
During a surgical extraction, the dentist requests a periosteal elevator. What is the function
of this instrument?
,A. To remove bone surrounding the tooth
B. To reflect the gingival tissue and periosteum from bone
C. To luxate the tooth from the socket
D. To suture the extraction site closed
Correct Answer: B
Explanation: A periosteal elevator separates soft tissue from bone, creating a clean surgical
field and protecting underlying structures during extraction procedures.
Question 5
A patient reports taking warfarin (Coumadin) during the medical history review. The dentist
is planning a tooth extraction. What is the MOST appropriate chairside action?
A. Proceed with the extraction as planned since warfarin only affects cardiac function
B. Alert the dentist immediately because anticoagulant therapy increases bleeding risk
C. Ask the patient to stop taking warfarin for one week before the procedure
D. Document the medication and schedule the extraction for the next day
Correct Answer: B
Explanation: Anticoagulants significantly increase hemorrhage risk during invasive
procedures; the dentist must assess INR levels and may consult the physician before
proceeding.
Question 6
, When transferring a hinged instrument such as a forceps to the dentist, which technique is
correct?
A. Place the handles directly into the dentist's palm with the hinge oriented toward you
B. Transfer with the working end pointing toward the patient
C. Orient the hinge so the dentist's fingers grasp the handles in a ready-to-use position
D. Set the instrument on the tray for the dentist to retrieve independently
Correct Answer: C
Explanation: Hinged instruments require transfer with handles accessible and hinge
positioned so the dentist can immediately engage the patient without repositioning.
Question 7
A patient scheduled for amalgam restoration on tooth #30 has a history of epilepsy. During
the procedure, the patient begins to experience a seizure. What is the FIRST priority action?
A. Place a bite block to keep the mouth open and continue the procedure
B. Clear the oral cavity of instruments and materials, then protect the patient from injury
C. Administer oxygen via nasal cannula immediately
D. Restrain the patient's limbs to prevent injury
Correct Answer: B
Explanation: During a seizure, removing oral foreign bodies prevents aspiration, and
protecting the patient from physical injury is the immediate priority before medical
management.
