22 Chairside Assisting Practice Questions & Answers

1. 1. A right-handed dentist is placing a restoration and the assistant must position the stool and mobile cart. Using the clock concept with the patient's head at 12 o'clock, which range is the assistant's zone?

   • A.12 o'clock to 2 o'clock
   • B.7 o'clock to 12 o'clock
   • C.4 o'clock to 7 o'clock
   • D.2 o'clock to 4 o'clock✓ Answer

   For a right-handed operator the clock is divided into operator's zone (7 to 12), static/set-up zone (12 to 2), assistant's zone (2 to 4) and transfer zone (4 to 7). The assistant sits on the patient's left in the 2-to-4 range so that suction, air-water syringe and instrument exchange all happen across the transfer zone without reaching over the operator's hands.

   Source: DANB General Chairside Assisting Exam Outline, Domain III: Chairside Dentistry - four-handed technique (zones of activity); ADA four-handed dentistry guidanceReport a problem with this question

2. 2. A practice hires a left-handed dentist, and the assistant who has always worked with right-handed operators must re-orient. For a left-handed operator, in which range of the clock does instrument transfer take place?

   • A.2 o'clock to 4 o'clock
   • B.5 o'clock to 8 o'clock✓ Answer
   • C.10 o'clock to 12 o'clock
   • D.4 o'clock to 7 o'clock

   The zones simply mirror for a left-handed operator: operator's zone 12 to 5, transfer zone 5 to 8, assistant's zone 8 to 10, static zone 10 to 12. The transfer zone always lies between the operator and the assistant over the patient's chest, so it moves to the patient's right side when the operator works left-handed.

   Source: DANB General Chairside Assisting Exam Outline, Domain III four-handed technique (zones of activity, left-handed operator); Bird & Robinson, Modern Dental Assisting, chairside deliveryReport a problem with this question

3. 3. An assistant is adjusting her operating stool at the start of a long restorative appointment. Which seated position is correct for the assistant relative to the operator?

   • A.At exactly the same height as the operator, with one foot on the floor for balance
   • B.Approximately 4 to 6 inches lower than the operator so the operator's view is not blocked
   • C.As low as the stool allows, leaning forward over the patient's chest
   • D.Approximately 4 to 6 inches higher than the operator, thighs parallel to the floor and feet on the base ring✓ Answer

   Seating the assistant about 4 to 6 inches higher than the operator lets her see over the operator's hands into the oral cavity, which is what makes anticipation and accurate evacuation possible. The thighs stay parallel to the floor with the feet supported on the stool's base ring and the abdominal bar across the ribs, so the back stays neutral and the assistant is not leaning or twisting.

   Source: DANB General Chairside Assisting Exam Outline, Domain III - seating and positioning of patient and dental team; dental ergonomics guidanceReport a problem with this question

4. 4. During a single-handed instrument transfer, where should the exchange between assistant and operator take place?

   • A.In the transfer zone, over the patient's chest and below the chin✓ Answer
   • B.Behind the patient's head, out of the patient's sight entirely
   • C.Directly over the patient's face, so the operator sees the instrument coming
   • D.Over the assistant's mobile cart, with the operator reaching back

   All transfers occur in the transfer zone over the patient's chest and below the chin so that a dropped instrument cannot fall on the patient's face or into the eyes, and so the operator's fulcrum hand barely moves. Passing behind the head or over the cart forces the operator to break the fulcrum and look away from the field.

   Source: DANB General Chairside Assisting Exam Outline, Domain III - transferring instruments; Bird & Robinson, Modern Dental Assisting, instrument transferReport a problem with this question

5. 5. The dentist is ready for extraction forceps during a surgical procedure. How should the assistant transfer this hinged instrument?

   • A.Hold it near the hinge and deliver it with the handles open, working end oriented for the arch being treated✓ Answer
   • B.Hold both handles closed together and place the beaks into the operator's palm
   • C.Pass it handle-first across the patient's forehead so the beaks stay clear of the tray
   • D.Lay it on the patient's chest so the operator can pick it up when ready

   Hinged instruments such as forceps, scissors and needle holders are held at the hinge and delivered with the handles open so the operator's fingers slip straight into the handles in the position of use. If the operator has to rotate or reposition the instrument after receiving it the transfer has failed, and passing over the face risks dropping it on the patient.

   Source: DANB General Chairside Assisting Exam Outline, Domain III - instrument transfer (hinged instruments); Bird & Robinson, Modern Dental AssistingReport a problem with this question

6. 6. An assistant is setting up a tray and encounters an unfamiliar hand instrument. Which feature of the instrument most directly tells her what it is designed to do and where it is used?

   • A.The overall length of the handle
   • B.The finish and weight of the handle material
   • C.The design of the working end together with the number and angulation of the bends in the shank✓ Answer
   • D.The color-code band on the handle

   Every hand instrument has a handle, a shank and a working end; the working end (blade, nib, point or beaks) defines the function, while the shank angulation defines access, since a straight or slightly angled shank reaches anterior teeth and multiple bends carry the working end to posterior teeth without the handle hitting the face. Color-code bands only identify which tray setup an instrument belongs to.

   Source: DANB General Chairside Assisting Exam Outline, Domain III - preparing trays and instruments; Bird & Robinson, Modern Dental Assisting, instrument design (handle, shank, working end)Report a problem with this question

7. 7. The dentist is about to begin a high-speed preparation on a mandibular right posterior tooth. Which describes correct use of the high-volume evacuator (HVE) by the assistant?

   • A.Wait until the handpiece is in the mouth, then slide the HVE onto the same surface the operator is preparing
   • B.Use only the saliva ejector for the preparation and add the HVE if the patient complains about water
   • C.Hold the HVE on the same side as the bur so both are aimed at the same surface
   • D.Place the HVE tip first, on the tooth surface opposite the one being prepared, with the beveled edge toward the tooth and slightly beyond the occlusal surface✓ Answer

   The HVE is positioned before the handpiece so the assistant is not competing with the operator's hand and mirror for space, and it is placed on the surface opposite the one being cut, with the bevel toward the tooth, so the tip captures water spray and aerosol at their source while keeping the field visible. A saliva ejector is low-volume only and cannot control spray from a high-speed handpiece.

   Source: DANB General Chairside Assisting Exam Outline, Domain III - maintaining the field of operation (oral evacuation, moisture control)Report a problem with this question

8. 8. An assistant is using a saliva ejector for low-volume evacuation during a long appointment. Which instruction best prevents backflow of previously suctioned fluid into the patient's mouth?

   • A.Tell the patient not to close the lips tightly around the ejector tip✓ Answer
   • B.Switch the ejector to full high-volume suction pressure
   • C.Ask the patient to seal the lips firmly around the tip so it stays in place
   • D.Keep the tip pressed against the floor of the mouth throughout the procedure

   When the patient seals the lips around a low-volume ejector tip, a partial vacuum forms in the mouth; if pressure in the suction line then drops below the pressure in the mouth, fluid already in the tubing can flow back through the tip. Coaching the patient to rest the lips loosely on the tip breaks that seal, and pressing the tip into soft tissue only causes tissue trauma without addressing backflow.

   Source: DANB General Chairside Assisting Exam Outline, Domain III - oral evacuation; CDC dental infection prevention guidance on saliva ejector backflowReport a problem with this question

9. 9. Before beginning a restoration under a dental dam, the assistant ties a length of dental floss to the clamp that will be placed on the anchor tooth. What is the reason for this ligature?

   • A.So the dam material can be inverted more easily into the sulcus
   • B.So the clamp is held tightly enough to stop saliva from leaking around the anchor tooth
   • C.So the clamp does not overheat while the high-speed handpiece is running
   • D.So the clamp can be retrieved immediately if it slips off or a bow or jaw fractures, preventing the patient from swallowing or aspirating it✓ Answer

   A clamp under spring tension can spring off the tooth or fracture, and the isolated field sits directly over the airway, so a floss safety line gives the team an immediate way to pull the clamp or its fragments out of the mouth. Preventing marginal leakage is a different problem, solved by inverting the dam rather than by the ligature.

   Source: DANB General Chairside Assisting Exam Outline, Domain III - dental dam application and maintaining the field of operation (aspiration prevention)Report a problem with this question

10. 10. A dental dam is in place with correctly sized punch holes and a well-seated clamp, but saliva is seeping onto the preparation around the necks of the isolated teeth. What should be done to correct the leakage?

    • A.Invert (tuck) the edge of the dam material into the gingival sulcus using air and a blunt instrument✓ Answer
    • B.Repunch the dam with larger holes and reapply it
    • C.Move the frame closer to the patient's chin to increase tension
    • D.Apply additional water-soluble lubricant to the dam material

    Inversion turns the cut edge of the dam down into the gingival sulcus so the seal is made against tooth structure apical to the margin, which is what stops salivary seepage; drying the tooth with air while tucking with a blunt instrument is the standard technique. Enlarging the holes would make leakage worse, and lubricant only eases passage of the material through contacts.

    Source: DANB General Chairside Assisting Exam Outline, Domain III - dental dam (inversion and moisture control)Report a problem with this question

11. 11. During a Class II amalgam restoration the caries has been removed, a liner has been placed, and the tooth is isolated. What does the assistant prepare and pass next?

    • A.The finishing burs and polishing points for the final contour
    • B.The condenser, so the operator can begin packing increments immediately
    • C.The carver and articulating paper to check the occlusion
    • D.The matrix retainer with the band assembled and a wedge for the interproximal, before any amalgam is triturated✓ Answer

    A Class II preparation has an open proximal box, so the matrix band and wedge must be in place to give the restoration a wall and a proper contact before any material is triturated and carried to the tooth. Amalgam is condensed, carved and checked only after the matrix is seated, and triturating early wastes working time because the mix begins to set immediately.

    Source: DANB General Chairside Assisting Exam Outline, Domain III - cavity preparation and restoration, matrix bands (procedure sequence)Report a problem with this question

12. 12. The assistant has assembled the local anesthetic syringe for an injection. How should the loaded syringe be handled and transferred?

    • A.Pass it below the patient's chin and out of the patient's line of sight with the needle sheath in place, and recap afterward using a one-handed scoop or a mechanical recapping device✓ Answer
    • B.Place it uncapped on the bracket tray so the operator can pick it up without a transfer
    • C.Pass it across the patient's chest at eye level so the patient can see the dentist is prepared
    • D.Remove the needle sheath before transfer and recap it afterward by holding the cap in the free hand

    The syringe is passed low, below the chin and behind the patient's line of sight, because seeing the needle raises anxiety and can trigger a vasovagal response, and the sheath stays on until the operator is at the injection site. Recapping is done one-handed with a scoop technique or a mechanical device so the free hand is never placed opposite an exposed contaminated needle.

    Source: DANB General Chairside Assisting Exam Outline, Domain III - topical and local anesthetic (assisting and needle safety); OSHA Bloodborne Pathogens Standard, safe sharps handlingReport a problem with this question

13. 13. Midway through a crown preparation a healthy adult patient becomes pale and diaphoretic, says the room is spinning, and briefly loses consciousness. After the procedure is stopped, what is the assistant's first action?

    • A.Retrieve the AED and attach the pads
    • B.Place the patient supine with the legs slightly elevated✓ Answer
    • C.Sit the patient upright and have the patient rebreathe into cupped hands
    • D.Give the patient orange juice or glucose gel by mouth

    Syncope is the most common medical emergency in the dental office and results from transient cerebral hypoperfusion, so placing the patient supine with the legs slightly raised restores blood flow to the brain and is the first step. Loosening tight clothing, a cold compress, oxygen and monitoring of vital signs follow, and nothing is given by mouth to a patient who is not fully conscious.

    Source: DANB General Chairside Assisting Exam Outline, Domain I - medical conditions that can cause emergencies; ADA guidance on managing medical emergencies (syncope)Report a problem with this question

14. 14. An anxious patient begins breathing rapidly and deeply before an injection, complains of tingling in the fingers and lips, and says she feels light-headed. Which management is correct?

    • A.Lay her flat and start high-flow supplemental oxygen by mask
    • B.Give oxygen and a dose of the patient's bronchodilator inhaler
    • C.Place glucose gel in the buccal vestibule and continue oxygen
    • D.Sit her upright, calm her, and have her rebreathe her own exhaled air; supplemental oxygen is not indicated✓ Answer

    Hyperventilation blows off carbon dioxide and produces respiratory alkalosis, which causes the tingling and light-headedness; the patient is not hypoxic, so this is the one common dental office emergency in which supplemental oxygen is not given. Rebreathing exhaled air from cupped hands, a paper bag or a nasal hood restores carbon dioxide, and sitting upright plus reassurance addresses the anxiety that triggered it.

    Source: DANB General Chairside Assisting Exam Outline, Domain I - respiratory emergencies; ADA guidance on office medical emergencies (hyperventilation)Report a problem with this question

15. 15. A patient with diabetes who skipped breakfast becomes shaky, confused and sweaty during treatment, and then becomes unresponsive. What is the correct management for the assistant to support?

    • A.Pour orange juice into the mouth to raise the blood sugar quickly
    • B.Wait ten minutes to see whether the patient wakes on his own before calling for help
    • C.Give nothing by mouth, position the patient supine, activate EMS, and provide oxygen while monitoring vital signs✓ Answer
    • D.Sit the patient upright and have him rebreathe into a paper bag

    A conscious hypoglycemic patient can be given an oral carbohydrate, but once the patient is unresponsive the protective airway reflexes are lost and anything placed in the mouth can be aspirated, so the rule is nothing by mouth plus immediate activation of emergency medical services. Definitive treatment of an unconscious hypoglycemic patient requires parenteral glucose or glucagon, which oral intake cannot accomplish.

    Source: DANB General Chairside Assisting Exam Outline, Domain I - endocrine emergencies (hypoglycemia/insulin shock); ADA medical emergency management guidanceReport a problem with this question

16. 16. Minutes after taking an antibiotic in the office, a patient develops hives, wheezing, swelling of the lips and tongue, and rapidly falling blood pressure. Which agent from the emergency kit is the single most important treatment?

    • A.An oral antihistamine tablet
    • B.A nitroglycerin tablet placed sublingually
    • C.An ammonia inhalant held under the nose
    • D.Injectable epinephrine given intramuscularly✓ Answer

    Anaphylaxis is a rapidly progressing reaction in which bronchoconstriction and vasodilation can be fatal within minutes, and injectable epinephrine is the only emergency drug that reverses both quickly, which is why it is considered the most important injectable drug in the kit. Antihistamines act too slowly and are reserved for mild delayed skin reactions, and EMS must be activated while the patient is positioned and the airway supported.

    Source: DANB General Chairside Assisting Exam Outline, Domain I - allergic emergencies; ADA emergency kit guidance (epinephrine as primary injectable drug for anaphylaxis)Report a problem with this question

17. 17. A patient with a history of epilepsy has a generalized convulsive seizure in the chair while instruments and a dental dam are in the mouth. What should the assistant do?

    • A.Clear instruments and the dam from the mouth, lower the chair, move objects away and protect the patient from injury without restraining him✓ Answer
    • B.Place a padded tongue blade between the teeth to protect the tongue
    • C.Sit the patient fully upright and offer sips of water as soon as movement starts
    • D.Hold the patient's arms and legs firmly to stop the movements

    Management of a convulsive seizure is entirely protective: remove anything from the mouth that could be aspirated or broken, lower the chair and clear the surroundings, and time the event. Restraining a seizing patient can cause fractures and soft tissue injury, and forcing an object between the teeth risks broken teeth and airway obstruction; airway support and oxygen are provided after the movements stop, and prolonged or repeated seizures require EMS.

    Source: DANB General Chairside Assisting Exam Outline, Domain I - neurologic emergencies (seizure management); ADA guidance on office medical emergenciesReport a problem with this question

18. 18. A patient with known angina develops crushing chest pain during treatment that is not relieved by his usual sublingual nitroglycerin. While the dentist stays with the patient, what is the assistant's role?

    • A.Lay the patient flat and complete the treatment once the pain eases
    • B.Reschedule the appointment and walk the patient to his car so he can drive to an emergency room
    • C.Wait until the patient loses consciousness before calling for outside help
    • D.Activate EMS immediately and bring the emergency kit, oxygen and the AED to the operatory, then help monitor and record vital signs and times✓ Answer

    Chest pain that does not respond to nitroglycerin must be treated as a possible myocardial infarction, which can progress to cardiac arrest, so definitive care depends on how fast emergency medical services arrive and how fast an AED is at the chairside. The office emergency plan assigns one team member to stay with the patient while another calls EMS and brings the kit, oxygen and AED, and a patient with possible cardiac ischemia is never allowed to drive himself.

    Source: DANB General Chairside Assisting Exam Outline, Domain I - cardiovascular emergencies; ADA office emergency preparedness (team roles, EMS activation, AED availability)Report a problem with this question

19. 19. While updating a health history, a patient reports that he carries nitroglycerin for chest pain and has recently started a prescription medication for erectile dysfunction. What should the assistant do with this information?

    • A.Record it and flag the combination to the dentist before treatment, because nitroglycerin taken with an erectile dysfunction drug can cause a dangerous drop in blood pressure✓ Answer
    • B.Tell the patient to stop taking the erectile dysfunction medication before dental appointments
    • C.Record it but take no further action, since erectile dysfunction drugs have no dental relevance
    • D.Remove the nitroglycerin from the office emergency kit for the day

    Nitroglycerin and phosphodiesterase-5 inhibitors used for erectile dysfunction are both vasodilators, and together they can produce profound, life-threatening hypotension, so the dentist must know before nitroglycerin would ever be given in an emergency. The assistant's role is to record the history accurately and bring findings to the dentist's attention; the assistant does not diagnose, prescribe, or tell a patient to alter medications ordered by a physician.

    Source: DANB General Chairside Assisting Exam Outline, Domain I/I - health history and medical conditions affecting treatment; Little et al., Dental Management of the Medically Compromised Patient (nitrate/PDE-5 inhibitor interaction)Report a problem with this question

20. 20. An assistant is giving postoperative instructions after a simple extraction. Which instruction addresses the greatest risk to the healing socket, and why?

    • A.Apply heat to the face for the first several hours to speed healing
    • B.Chew on the extraction side as soon as the anesthetic wears off to stimulate circulation
    • C.Rinse forcefully with warm salt water every hour on the day of surgery to keep the socket clean
    • D.Avoid drinking through a straw, smoking and vigorous rinsing for the first 24 hours, because the suction and agitation can dislodge the clot✓ Answer

    Healing depends on an intact blood clot filling the socket; negative pressure from a straw or cigarette, and forceful rinsing, can pull the clot out and leave exposed bone, producing alveolar osteitis (dry socket) with severe pain typically two to four days later. Cold, not heat, is used the first day to limit swelling, and the patient is told to bite firmly on gauze and eat soft foods away from the site.

    Source: DANB General Chairside Assisting Exam Outline, Domain II/III - pre- and post-treatment instructions, extractions and dry socketReport a problem with this question

21. 21. An assistant realizes she charted a treatment note in the wrong patient's record. How should the erroneous entry be corrected?

    • A.Erase or cover the entry with correction fluid and rewrite it accurately
    • B.Leave the entry as written and add the correct note in a different chart without referencing it
    • C.Destroy the page and start a new record sheet for that patient
    • D.Draw a single line through the entry so it remains readable, write the correction, and initial and date the change✓ Answer

    The patient record is a legal document and must show a complete, unaltered history of what was written, so an error is crossed out with a single line that leaves the original readable, with the correction, initials and date added. Erasing, covering with correction fluid or destroying a page makes the record appear altered and destroys its evidentiary value if the treatment is ever questioned.

    Source: DANB General Chairside Assisting Exam Outline, Domain II - maintenance of patient records as legal documents (charting corrections)Report a problem with this question

22. 22. Before a surgical procedure the dentist reviews the informed consent discussion with the patient while the assistant documents it. Which element must the consent include for it to be valid?

    • A.The names and credentials of every staff member present
    • B.A guarantee that the treatment will succeed
    • C.A statement that the patient waives the right to ask further questions
    • D.The alternatives to the proposed treatment, including the option of no treatment and its likely consequences✓ Answer

    Consent is informed only when the patient can weigh real choices, so the discussion must cover the proposed procedure, its risks and benefits, reasonable alternatives, and what is likely to happen if nothing is done, with the patient given the chance to ask questions. No treatment outcome may be guaranteed, and the assistant documents that the discussion took place rather than substituting her own explanation of the treatment plan.

    Source: DANB General Chairside Assisting Exam Outline, Domain II - legal responsibilities and documentation (informed consent elements)Report a problem with this question

Practice questions based on the DANB Radiation Health and Safety (RHS), Infection Control (ICE), and General Chairside Assisting (GC) content outlines, CDC dental infection-prevention guidance, the OSHA Bloodborne Pathogens Standard, and ADA/FDA radiographic selection criteria. DANB, CDA, RHS, ICE, and GC are marks of the Dental Assisting National Board; this site is not affiliated with or endorsed by DANB. The duties a dental assistant may legally perform — and any radiography permit or certification required — are set by your own state dental board. Confirm current requirements with that board and with DANB before testing. About the DANB exams →