Free DANB GC Practice Test: 95 Questions With Answers

Correct answer: B. Blood pressure 116/76 mmHg, pulse 72 beats per minute, respirations 16 per minute

For a resting adult, normal ranges are about 90/60 to 120/80 mmHg for blood pressure, 60 to 100 beats per minute for pulse and 12 to 18 breaths per minute. Only the 116/76, 72, 16 set sits inside all three. The 142/92 reading is above the normal blood pressure range, a pulse of 108 is above 100, and 26 breaths per minute is well above 18. Any abnormal reading is recorded exactly as measured and brought to the dentist before treatment.

Source: MedlinePlus — Vital signs — Normal ranges for the average healthy adult at rest

Correct answer: D. It will tend to read falsely high

A cuff that is too small for the arm tends to overstate blood pressure. In a study reported by the American Heart Association, using a too-small cuff produced falsely higher readings in many participants. A snug fit does not fix a cuff that is the wrong size; choose a cuff that matches the arm. Cuff size affects the blood pressure reading itself, not just the pulse.

Source: American Heart Association News — When it comes to accurate blood pressure readings, cuff size matters (2022) — Study findings on too-small cuffs

Correct answer: C. Flag the warfarin for the dentist before treatment begins

Warfarin is an anticoagulant that can cause serious bleeding, and patients are told to inform their dentist before dental procedures. Its effect is tracked with an INR blood test, which the dentist may want before surgery. The ADA notes warfarin is generally not changed for dental procedures, and any change is a decision for the patient's physician, never the assistant. Ignoring or deleting the medication hides a real bleeding risk.

Sources: MedlinePlus — Warfarin — Important warning; What special precautions should I follow?; ADA Oral Health Topics — Oral Anticoagulant and Antiplatelet Medications and Dental Procedures — Warfarin; INR

Correct answer: A. Permanent mandibular right first molar

Universal numbering runs from #1 (maxillary right third molar) across to #16, then drops to #17 (mandibular left third molar) and runs back to #32 (mandibular right third molar). That makes #30 the mandibular right first molar. The mandibular left first molar is #19, the maxillary right first molar is #3 and the mandibular right second molar is #31.

Source: HL7 FHIR Dental Data Exchange — Dental Universal Numbering System value set (ADA Universal codes) — Value set table, codes 3, 19, 30, 31

Correct answer: C. Help her sit upright and use her quick-relief inhaler

Wheezing, coughing and chest tightness in a patient with asthma point to an asthma attack. First aid is to help the person sit up straight and use their quick-relief medicine, usually a short-acting bronchodilator such as albuterol, and to call 911 if breathing does not improve. Lying flat makes breathing harder, a paper bag does nothing for narrowed airways, and glucose treats low blood sugar, not bronchospasm.

Sources: American Red Cross — Asthma attack first aid — First aid steps; MedlinePlus — Asthma: quick-relief drugs — Short-acting beta-agonists

Correct answer: A. Mesial, occlusal and distal

MOD stands for mesial, occlusal, distal. It describes a restoration that covers the occlusal (chewing) surface plus both proximal surfaces of a posterior tooth. DANB's own GC acronym list defines MOD this way. A lingual surface would add an L to the abbreviation, and a restoration without the occlusal surface would not be written MOD.

Source: DANB — GC Exam Outline and References (effective 07/01/2022) — Acronyms, p. 8 (MOD)

Correct answer: A. Overjet

Overjet is the horizontal overlap of the maxillary incisors over the mandibular incisors, measured parallel to the occlusal plane. Overbite is the vertical overlap, measured perpendicular to the occlusal plane. An open bite means the teeth do not overlap vertically, and a crossbite means upper teeth sit inside the lower teeth.

Source: National Library of Medicine MeSH — Overbite — Scope note

Correct answer: B. Lateral pterygoid

The lateral pterygoid is the only muscle of mastication that depresses the mandible, helped by gravity, and it also protrudes the jaw and moves it side to side. The masseter, temporalis and medial pterygoid all elevate the mandible to close the mouth; the medial pterygoid also assists protrusion but does not open the jaw.

Source: StatPearls — Anatomy, Head and Neck, Mastication Muscles (NCBI Bookshelf) — Function

Correct answer: A. Call 911 immediately and note the time the symptoms started

Face drooping, arm weakness and speech difficulty are classic stroke warning signs. CDC's B.E. F.A.S.T. guidance says to call 911 right away and note when symptoms first appeared, because treatment decisions depend on timing. Waiting wastes critical time, CDC advises against driving the person yourself, and nitroglycerin is for angina, not stroke.

Source: CDC — Signs and Symptoms of Stroke — B.E. F.A.S.T.

Correct answer: A. Anesthetic spread to the facial nerve in the parotid gland

If anesthetic is deposited too far back, it can spread into the parotid gland, where the facial nerve runs. The result is a sudden, one-sided inability to close the eye and a drooping mouth that usually resolves within hours as the anesthetic wears off. Protecting the eye, for example with a patch and lubricant, is part of management. The lingual nerve supplies sensation to the tongue, not facial muscles, and an allergic reaction or trismus would look different.

Sources: Shettar et al., Facial nerve palsy after inferior alveolar nerve block — systematic review, Cureus 2025;17(5):e84966 — Mechanism; immediate-type palsy; IJERPH 2022 — Facial nerve palsy after inferior alveolar nerve block: systematic review — Section 1, Introduction

Correct answer: B. Class II

Class II lesions are on the proximal (mesial or distal) surfaces of premolars and molars. Class I involves pits and fissures, Class III is a proximal surface of an anterior tooth without the incisal angle, and Class VI is an incisal edge or cusp tip.

Source: University of Toronto Faculty of Dentistry — Cavity Preparations — Black's classification, p. 3

Correct answer: D. Document the refusal and the discussion in the record

Patients have the right to refuse care. The ADA advises documenting the refusal carefully, including what was discussed, the patient's reasons and their understanding of the possible health consequences. Treating without consent is not an option, leaving it out of the record removes important protection for patient and practice, and refusing one service is not grounds for immediate dismissal.

Source: ADA — Managing Patients: Informed Consent and Refusal — Informed Consent/Refusal

Correct answer: B. Calmly reassure her and coach slower breathing

Rapid breathing with tingling and lightheadedness in an anxious, alert patient fits hyperventilation. Management is reassurance in a calm voice and coaching slower breathing. Dental emergency training materials warn not to give oxygen to a hyperventilating patient, because the problem is breathing off too much carbon dioxide, not a lack of oxygen. Epinephrine is for anaphylaxis, and glucose is for low blood sugar.

Sources: MedlinePlus — Hyperventilation — Home Care; Northwest Portland Area Indian Health Board — Medical Emergencies for Dental Providers — Recognition: Hyperventilation (caution)

Correct answer: B. Intramuscular epinephrine

Hives, airway symptoms and falling blood pressure together point to anaphylaxis. Epinephrine is the first-line drug and should be used right away; for adults, the FDA-approved label gives 0.3 to 0.5 mg of 1 mg/mL epinephrine injected into the anterolateral thigh. Antihistamines may be added later but do not reverse airway swelling or shock. Nitroglycerin lowers blood pressure, and an inhaler alone does not treat the whole reaction.

Sources: MedlinePlus — Anaphylaxis — First Aid; FDA-approved Adrenalin (epinephrine) prescribing information, rev. 06/2026 — Section 2.2, Anaphylaxis dosing

Correct answer: D. Keep her safe, put nothing in her mouth and time the seizure

CDC seizure first aid is to keep the person safe, not to stop the movements. Do not put anything in the mouth, do not hold the person down and time the seizure. Call 911 if it lasts longer than 5 minutes or if other danger signs appear, such as trouble breathing or injury. Giving fluids to someone who is not fully awake risks choking.

Source: CDC — First Aid for Seizures — Do not / When to call 911

Correct answer: D. Call 911 right away

For chest pain treated with nitroglycerin, patients are told to wait 5 minutes after the first dose and call 911 if symptoms are not better, are worse, or come back. Pain that worsens after nitroglycerin can mean a heart attack. Waiting longer or continuing treatment delays emergency care, and glucose does not treat cardiac chest pain.

Source: MedlinePlus — Angina: when you have chest pain — How to Treat Your Chest Pain

Correct answer: C. Right away, say "Great job holding so still!"

Positive reinforcement rewards a desired behavior so it is more likely to happen again. Specific praise given right after the behavior is the classic example in AAPD behavior guidance. Waiting until the end weakens the link to the behavior, a raised voice is a different technique (voice control), and a threat about a parent's reaction is not reinforcement.

Source: AAPD — Behavior Guidance for the Pediatric Dental Patient (Reference Manual 2025) — Positive reinforcement and descriptive praise, p. 384

Correct answer: C. Have the drink with a meal instead of sipping it all day

Each sugary sip feeds acid-producing bacteria, and frequent between-meal exposure keeps teeth losing minerals. The ADA advises patients at risk to reduce both the amount and the frequency of carbohydrate intake, and NIDCR notes that frequent sugar intake keeps minerals leaving the enamel. Moving the drink to one sitting reduces exposures; a single rinse or harder brushing does not undo all-day sipping.

Sources: ADA Oral Health Topics — Caries Risk Assessment and Management — Diet counseling (amount and frequency); NIDCR — Tooth Decay: more information — Causes; prevention

Correct answer: A. It helps restore lost minerals and makes enamel resist acid

Acid from plaque bacteria dissolves minerals from the tooth surface. CDC explains that fluoride helps replace those lost minerals and makes enamel more resistant to acid. It does not sterilize the mouth, it cannot fill an existing cavity, and sealing grooves is the job of a sealant, not fluoride.

Source: CDC — About Fluoride — How Fluoride Prevents Tooth Decay

Correct answer: C. At a 45-degree angle to the gums

The ADA teaches placing the toothbrush at a 45-degree angle to the gums and using short, tooth-wide strokes, which lets the bristles reach plaque at the gumline. Scrubbing flat and side to side or pointing bristles away from the gums misses that area, and the ADA recommends soft-bristled brushes rather than hard ones.

Source: ADA MouthHealthy — Brushing Your Teeth — Proper brushing technique

Correct answer: D. The two conditions can each make the other worse

NIDCR explains that people with diabetes are more likely to develop gum disease and that having gum disease may make blood sugar harder to control. It is a two-way relationship, which is why periodontal health gets extra attention in these patients. Nothing limits the link to one type of diabetes, and high blood sugar harms rather than protects the gums.

Source: NIDCR — Diabetes and oral health — Gum disease

Correct answer: C. Keep it in water whenever it is out of the mouth

The ADA says dentures should be kept covered in water when not worn so they do not warp, and brushed daily with a soft brush and a non-abrasive cleanser. CDC advises removing dentures overnight if possible and cleaning them daily. Abrasive toothpaste and very hot water can damage the denture, air-drying risks warping, and weekly cleaning is not enough.

Sources: ADA MouthHealthy — Dentures — Caring for dentures; CDC — Oral Health Tips for Adults — Denture care

Correct answer: D. Watch that the child doesn't bite the numb lip, cheek or tongue

Children often bite or chew a numb lip, cheek or tongue, causing soft tissue injury. AAPD guidance says post-treatment instructions should cover how long the anesthesia lasts and ways to reduce the risk of biting. Warm compresses and hourly rinses do not address that risk, and assuming children will not notice is exactly how these injuries happen.

Source: AAPD — Use of Local Anesthesia for Pediatric Dental Patients (Reference Manual 2025) — Postoperative soft tissue injury; Recommendations

Correct answer: B. It is early decay that can still be stopped or reversed

A white spot where minerals have been lost is an early sign of decay. NIDCR notes that decay can be stopped or reversed at this stage, for example with fluoride and better plaque control. That makes immediate drilling unnecessary in most cases, while ignoring the spot risks it becoming a cavity.

Source: NIDCR — Tooth Decay: more information — Causes; prevention

Correct answer: A. A patient who is pregnant

FDA's 2020 recommendations name groups at higher risk from mercury exposure, including pregnant women, women planning to become pregnant, nursing women, children (especially those under 6), people with certain neurological diseases or impaired kidney function, and people sensitive to mercury or other amalgam components. The other patients are not in those groups. FDA also says not to remove existing amalgam fillings in good condition unless medically necessary.

Source: FDA — Recommendations for certain high-risk groups regarding mercury-containing dental amalgam (Sept. 24, 2020) — High-risk groups list

Correct answer: B. Within 30 days, with one 30-day extension allowed

The HIPAA Privacy Rule requires a covered entity to act on a request for access no later than 30 days after receiving it. It may extend that once by up to 30 more days if it gives the patient a written reason and an expected date before the first deadline passes.

Source: 45 CFR 164.524 — Access of individuals to protected health information (eCFR) — (b)(2)(i)–(iii)

Correct answer: C. Yes, with limited information and reasonable safeguards

HHS says covered entities may use sign-in sheets and call out patient names in waiting rooms, as long as the information disclosed is appropriately limited and reasonable safeguards are in place. A sign-in sheet should not display medical information that is not needed, such as the reason for the visit, and no separate authorization is required.

Source: HHS HIPAA FAQ — May health care providers use sign-in sheets or call out names? — Answer

Correct answer: B. The patient gets adequate notice and time to find another dentist

Section 2.F of the ADA Code says that once a dentist has undertaken a course of treatment, the dentist should not discontinue it without giving the patient adequate notice and the opportunity to obtain another dentist's services. Stopping without notice is patient abandonment. The Code does not require finishing every planned procedure regardless of circumstances, and the decision and notice belong to the dentist.

Source: ADA Principles of Ethics and Code of Professional Conduct (revised to Oct. 2024) — Section 2.F Patient Abandonment, p. 6

Correct answer: A. Readily accessible in the work area during every shift

OSHA's Hazard Communication Standard requires employers to keep a safety data sheet for each hazardous chemical they use and to make it readily accessible to employees in their work areas during each work shift. Locking it away, relying on a website or filing it with patient charts does not meet that requirement.

Source: 29 CFR 1910.1200 — Hazard Communication (Cornell LII) — (g)(1), (g)(8)

Correct answer: D. A one-handed scoop technique or a mechanical recapping device

OSHA's Bloodborne Pathogens Standard prohibits bending, recapping or removing contaminated needles unless no alternative is feasible or a specific dental procedure requires it. When recapping is required, it must be done with a mechanical device or a one-handed technique. Two-handed recapping and bending needles are exactly what the rule prevents, and passing an uncapped needle adds another chance for a stick.

Source: 29 CFR 1910.1030 — Bloodborne Pathogens (Cornell LII) — (d)(2)(vii)

Correct answer: C. 30 boxes

A reorder point is the expected demand during the delivery lead time plus safety stock. Lead-time demand is 4 boxes per day x 5 days = 20 boxes, and adding the 10-box safety stock gives 30. Reordering at 20 ignores the safety stock, 14 adds one day's use to the safety stock instead of multiplying daily use by lead time, and 50 counts the safety stock three times.

Source: University of Iowa, D. Bricker — Reorder Point (lecture slides) — Definition of reorder point

Correct answer: C. Free, after training, within 10 working days of assignment

OSHA requires employers to make the hepatitis B vaccination available at no cost to employees with occupational exposure, after they receive bloodborne pathogens training and within 10 working days of initial assignment. Waiting for an exposure, charging the employee or requiring a written request does not meet the standard; an employee may decline only by signing the required declination.

Source: 29 CFR 1910.1030 — Bloodborne Pathogens (Cornell LII) — (f)(1)(ii)(A), (f)(2)(i)

Correct answer: A. Supine, with the maxillary occlusal plane near perpendicular to the floor

For maxillary work the patient is reclined fully supine so the maxillary occlusal plane is as close to perpendicular to the floor as possible, giving the operator direct access and vision. A more upright position is used for the mandibular arch, where the mandibular occlusal plane is closer to parallel to the floor. Trendelenburg is an emergency position, not a routine working position.

Source: Dimensions of Dental Hygiene — Creating an Ergonomic Workspace — Positioning Patients

Correct answer: A. About 4 to 6 inches higher than the operator

The assistant sits about 4 to 6 inches higher than the operator so they can see over the operator's hands into the field without straining. Sitting level or lower blocks that view. Assistants' stools also have an abdominal or torso support so the assistant can lean forward safely while seated.

Source: Dentalcare CE643 — Four-Handed Dentistry: Strategies for Conserving Motion

Correct answer: A. Raise it gradually and let the patient sit up for a moment before standing

Sitting up quickly after lying back can cause postural (orthostatic) hypotension, a drop in blood pressure that makes the patient dizzy or faint. Prevention guidance is to bring at-risk patients upright gradually, over about 2 minutes, before they stand. Rushing the patient up skips that adjustment.

Source: Dentalcare CE516 — Managing Adult Medical Emergencies: Postural (Orthostatic) Hypotension — Table 2, Prevention

Correct answer: B. In their order of use

Four-handed dentistry places instruments in their sequence of use, typically left to right (or top to bottom), so the assistant can anticipate the next instrument and transfers stay smooth. Size or name order does not match how the procedure unfolds. Sterility is required but does not make random order efficient.

Sources: Dentalcare CE643 — Basic Tenets of Four-Handed Dentistry; Dentalcare CE643 — Assistant Requirements

Correct answer: C. Mouth mirror, explorer and cotton pliers

Tray setups typically start with the mouth mirror, explorer and cotton pliers, which are used for examining, detecting and carrying small items in nearly every procedure. Example setups for sealants and composite restorations list these three first, then add procedure-specific instruments such as excavators, matrix systems or surgical tools.

Source: Dentalcare CE673 — Procedures for Pit and Fissure Sealant Placement — Figure 6, Tray set-up

Correct answer: B. At the non-working end, working end aimed at the arch being treated

The assistant holds the incoming instrument at its non-working third so the operator can grasp it in a usable position. The working end is oriented for the arch: up for the maxilla and down for the mandible. The transfer uses positive pressure so the operator knows the instrument is there. Holding the working end risks contamination and injury.

Sources: Dentalcare CE643 — The Single-Handed Transfer; Dentalcare CE643 — Assistant Requirements

Correct answer: A. Palm-thumb (thumb-to-nose) grasp

Four-handed dentistry training identifies the palm-thumb, or thumb-to-nose, grasp as the grasp the assistant uses for the oral evacuator. It gives steady control of the tip while keeping the hand clear of the field. The pen grasp is used for most operative hand instruments, not the HVE.

Source: Dentalcare CE643 — Instrument Grasps

Correct answer: D. On the buccal mucosa, opposite the maxillary second molar

The parotid (Stensen's) duct opens at a small papilla on the inside of the cheek next to the maxillary second molar, which is why a dry angle or cotton roll is placed there to control saliva. The submandibular duct opens under the tongue near the lingual frenum, and there is no major salivary duct opening on the palate behind the central incisors.

Source: Radiopaedia — Parotid duct — Gross anatomy

Correct answer: B. On the most distal tooth being isolated

The clamp anchors the dam, so it goes on the most distal tooth in the isolated area. Hole sizes in the dam are matched to tooth size, with the larger holes for molars. Clamping the most anterior tooth or every tooth would not anchor the dam properly, and the tooth being restored is often inside the isolated area rather than at its end.

Sources: Small & Clawges — Using the Rubber Dam for Operative Dentistry, Inside Dental Assisting (2011) — Preparation of the Rubber Dam; Retainer Selection; Columbia University College of Dental Medicine — Rubber Dam

Source link currently unavailable; the original citation is retained.

Correct answer: A. Invert the dam edges into the sulcus around each tooth

Inverting the dam around the cervical area of each tooth, often with floss or air and an instrument, creates a tight seal against saliva. Holes that are too large cause leakage at the necks of the teeth, so bigger holes would make it worse. Removing the clamp loosens the dam rather than sealing it.

Source: NHS Education for Scotland — Rubber Dam: Hints and Tips — Winged technique

Correct answer: B. A non-latex dam, with latex products kept away from the patient

CDC notes that latex-allergic patients can be at risk from dental products including rubber dams and should be treated in a latex-safe environment with latex-containing products removed from their vicinity. Non-latex dams are available for this purpose. Gauze or short contact does not remove the risk, and a non-latex dam means isolation does not need to be skipped.

Sources: CDC — Guidelines for Infection Control in Dental Health-Care Settings, 2003 (MMWR 52/RR-17) — Contact Dermatitis and Latex Hypersensitivity; Small & Clawges — Using the Rubber Dam for Operative Dentistry, Inside Dental Assisting (2011) — Preparation of the Rubber Dam; Retainer Selection

Source link currently unavailable; the original citation is retained.

Correct answer: A. Smooth, accurate margins that don't impinge on the gingiva

Provisional margins should be smooth and accurate to avoid damaging the surrounding tissue. Before cementation, the margins, proximal contacts and occlusion are checked. Overextended or rough margins trap plaque and irritate the gingiva, and leaving the bite high causes discomfort rather than settling.

Sources: Becker — Provisional Trimming: The Choice Is Yours, Inside Dental Assisting (2009); University of Iowa D3 Prosthodontics Manual — Prep + Interim Appointment — Ch. 32

Source link currently unavailable; the original citation is retained.

Correct answer: D. Remove the excess cement and floss the contacts

After temporary cement sets, the excess is removed and the contacts are flossed so no cement is left against the gingiva or between teeth. Leftover cement irritates tissue and traps plaque; it does not seal anything. Waiting until the next visit leaves that irritation in place.

Source: University of Iowa D3 Prosthodontics Manual — Prep + Interim Appointment — Ch. 32

Correct answer: D. Their normal, habitual full bite

Bite records are meant to capture how the teeth normally fit together. Errors happen when the patient bites in a position other than their normal maximal intercuspal position, so practicing the closure before placing the material helps. Protruded, shifted or partial closures record a bite the patient does not use.

Source: Scott — Decrease Crown Seating Time With Better Bite Records, Inside Dentistry (2013)

Correct answer: A. Articulating paper

Articulating paper is the most common way to mark occlusal contacts in the mouth. When the patient taps and grinds, the paper marks contacts, and a heavy mark shows the interference to adjust. It works best on dry teeth. Disclosing solution shows plaque, a probe measures pockets and topical anesthetic numbs tissue.

Source: Babu & Nayar — Occlusion indicators: a review, J Indian Prosthodont Soc 2007;7(4) — Articulating paper

Correct answer: D. So each layer cures fully and shrinkage stress is lower

Conventional composites are placed in increments of up to about 2 mm so the curing light can fully polymerize each layer and to limit polymerization shrinkage and its stress on the tooth. Layering does not increase fluoride release, still requires a curing light for light-cured material, and does not replace the bonding step.

Source: Matéria (Rio de Janeiro) 2020 — incremental composite placement — Introduction

Correct answer: B. Orange blue-blocking glasses, shields or paddles

Curing lights emit intense blue light that can injure the retina. The ADA recommends orange blue-blocking glasses, tip-mounted shields or handheld paddles. Clear glasses do not filter blue light, and moving the tip away reduces the energy reaching the composite, which hurts the cure, so keep the tip close to the restoration and protect your eyes instead.

Source: ADA Oral Health Topics — Dental Curing Lights — Eye safety; irradiance and distance

Correct answer: C. Immediately, so it can be condensed before it starts to set

Manufacturer instructions say insertion should begin immediately after trituration, because amalgam has a limited working window, only a few minutes depending on set speed. Waiting lets it start to set so it cannot be condensed well. Amalgam is not rinsed before placement, and it sets on its own whether or not it has been carved.

Source: SDI amalgam instructions for use (Permite / Lojic+ / GS-80) — Insertion; working times

Correct answer: D. It tends to produce a tighter proximal contact

The separating ring slightly spreads the teeth while the thin sectional band is in place, so when the ring is removed the teeth close against the restoration. Laboratory testing found tighter Class II contacts with a sectional matrix and ring than with a circumferential matrix. It does not remove the need for wedges in general, is not limited to amalgam and has nothing to do with curing.

Source: Tolba et al. — Sectional vs circumferential matrix contacts, BMC Oral Health 2023;23:535 — Results; Conclusion

Correct answer: C. A clear plastic (Mylar) strip

Clear plastic Mylar strips are used for Class III and IV composites. The strip is pulled tight against the composite while it is cured, shaping the proximal surface and letting the curing light pass through. Metal bands like the Tofflemire are used for posterior restorations and would block the light.

Source: Dental Economics — Matrix system solves problems

Correct answer: A. Cut close to the tissue, then pull by the knot

The goal is to avoid pulling the contaminated part of the suture, the part that was exposed in the mouth, back through the tissue. Cutting close to the tissue on one side and pulling by the knot does that. Cutting far from the tissue or pulling an uncut suture drags contaminated thread through the wound.

Sources: Nursing Skills 2e (open textbook) — Checklist for Intermittent Suture Removal — Step 14; ITI/FOR — Suture removal (surgical aftercare)

Correct answer: B. Light-body is syringed around the preparation, and heavy-body fills the tray

The light-body (low-viscosity) material flows into fine detail, so it is injected all around the preparation and margins. The heavy-body tray material supports it and pushes it into place when the tray is seated. Reversing the roles loses margin detail, and an empty tray gives the light-body material nothing to hold it.

Source: Dalhousie Prosthodontics (OASIS) — Post and core impression technique

Correct answer: A. It slows absorption, lengthening anesthesia and reducing bleeding

A vasoconstrictor narrows blood vessels at the injection site, so the anesthetic is absorbed into the bloodstream more slowly. That keeps it working longer, lowers blood levels of the drug and helps control bleeding. Faster absorption would do the opposite, and vasoconstrictors neither reverse anesthesia nor replace topical anesthetic.

Source: Saraghi — Misconceptions related to vasoconstrictors for local dental anesthesia, CDEWorld (2015)

Correct answer: B. Do not use it; set it aside and use another cartridge

A small bubble in a cartridge is nitrogen and is not a concern, but a large bubble with an extruded stopper suggests the cartridge has frozen, and it should not be used. Other reasons to discard a cartridge include a corroded or rusted cap and cracked glass. Cartridges are not heat-sterilized, and forcing the stopper back does not fix the damage.

Sources: Dentalcare CE325 — Local Anesthesia in Pediatric Dentistry: Cartridge; CUNY City Tech DEN 2318 — Local Anesthesia Armamentarium (lecture slides) — Dental Anesthetic Cartridge Problems

Correct answer: A. Not for children under 2, due to methemoglobinemia risk

In 2018 FDA warned that over-the-counter oral benzocaine products should not be used to treat infants and children younger than 2 because of methemoglobinemia, a dangerous drop in the blood's ability to carry oxygen. Warning signs include pale, gray or blue skin, lips and nail beds, shortness of breath, fatigue, confusion, headache, lightheadedness and a fast heart rate.

Source: FDA Drug Safety Communication — Oral benzocaine products and methemoglobinemia (May 23, 2018)

Source link currently unavailable; the original citation is retained.

Correct answer: C. A light-cured resin barrier along the gingival margins

Light-cured resin barriers are applied along the gum margins before in-office bleaching to keep highly concentrated peroxide off the soft tissue. The ADA notes that improper barrier placement is one cause of gingival irritation. Petroleum jelly on the teeth would block the whitening gel, and fluoride varnish is not a barrier.

Sources: BMC Oral Health 2024;24:139 — Light-cured resin gingival barriers in in-office bleaching — Background; Methods; ADA Oral Health Topics — Tooth Whitening — Key Points; Patient Considerations; Gingival Irritation

Correct answer: B. No; whitening does not change tooth-colored restorations

The ADA states that only natural teeth can be whitened; tooth-colored restorations will not change color. After whitening, existing composites or crowns may no longer match and might need replacement to blend in. Whitening does not darken restorations either.

Source: ADA Oral Health Topics — Tooth Whitening — Key Points; Patient Considerations; Gingival Irritation

Correct answer: A. Stimuli move fluid in open dentinal tubules, triggering nerves

The hydrodynamic theory explains that cold, heat, air, touch or sweet and acidic foods cause fluid to move in exposed, open dentinal tubules. That movement stimulates receptors that signal nerves in the pulp, producing short, sharp pain. Enamel has no nerves, and the theory does not involve bacterial toxins or calculus.

Source: Dentalcare CE200 — Dentinal Hypersensitivity: Theories

Correct answer: C. Potassium nitrate calms the nerve; occluding agents plug tubules

Potassium nitrate raises potassium levels around the nerve, which changes its polarization and reduces nerve excitation; it typically takes a few weeks to work. Other agents, such as oxalates, strontium salts, stannous fluoride and calcium phosphates, occlude the tubules so fluid cannot move. Enamel does not regrow, and neither type works by bleaching.

Sources: Dentalcare CE200 — Potassium Nitrate Dentifrice; J Periodontal Implant Sci 2016;46(1):46–56 — dentin hypersensitivity agents — Introduction

Correct answer: C. A direct structural and functional bone-to-implant connection

Osseointegration is the direct structural and functional connection between living bone and the surface of a load-bearing implant. A soft tissue layer between bone and implant would mean the implant has not integrated. Cementing the crown is a restorative step, and titanium implants are not designed to dissolve.

Source: Int J Res Med Sci 2025 — Osseointegration in dental implants — Abstract

Correct answer: D. Metal instruments can scratch and roughen the titanium

Studies of implant instrumentation found that stainless steel curets and metal ultrasonic tips roughen titanium surfaces, which can affect biocompatibility and help plaque collect, while plastic curets did not roughen the surface. That is why plastic tips, plastic-tipped hand instruments and titanium implant scalers are used. Implants still need professional maintenance.

Sources: Sefo & Nakamura — Implant Instrumentation, Dimensions of Dental Hygiene 2013;11(6); Dentalcare CE468 — Instrumentation Around Dental Implant Restorations

Correct answer: C. Periosteal elevator

A periosteal elevator reflects the mucosa and periosteum together down to bone when a full-thickness flap is raised. A bone file smooths bone edges, a rongeur trims bone and a hemostat clamps or grasps tissue.

Source: StatPearls — Oral Surgery, Instruments (NCBI Bookshelf) — Function: periosteal elevators; rongeurs; bone files

Correct answer: B. Rongeur, then bone file

Rongeurs are used to trim and remove bone, such as a sharp prominence or uneven ridge, and the remaining bone edge is then smoothed with a bone file. Reversing the order would file bone that is about to be cut away. Periosteal elevators lift tissue, hemostats clamp and needle holders are for suturing.

Source: StatPearls — Oral Surgery, Instruments (NCBI Bookshelf) — Function: periosteal elevators; rongeurs; bone files

Correct answer: D. Mandibular incisors, canines, premolars and roots

The #151 is the mandibular universal forceps, designed for lower incisors, canines, premolars and roots. Its maxillary counterpart, the #150, is used for the same tooth types in the upper arch. Neither is designed as a molar forceps.

Sources: Hu-Friedy surgical catalog — #151 Cryer forceps; Hu-Friedy surgical catalog — #150 Cryer forceps

Correct answer: D. To release the pus collected in the abscess

In incision and drainage, the clinician finds the most fluctuant (soft, fluid-filled) point of the abscess, makes a small incision and lets the pus drain, using suction and gauze to remove it. It relieves pressure and pain but does not remove the tooth. Dressings for extraction sockets and biopsies are different procedures.

Source: Merck Manual Professional — How to Drain a Tooth Abscess — Step-by-Step Description

Correct answer: C. Tell the dentist and document the call for follow-up

Nerves running through the lower jaw can be injured during lower wisdom tooth removal, causing temporary or, rarely, permanent numbness of the lip, chin or tongue. Hospital guidance tells patients to contact the surgical team if numbness continues for a week or more. Telling her it will pass on its own or needs no follow-up skips the check that this guidance calls for.

Source: University Hospitals Sussex NHS — Removal of wisdom teeth under local anaesthetic (patient leaflet) — Risks: nerve damage

Correct answer: D. Cold packs, about 20 minutes at a time, for the first 24–48 hours

Post-surgical instructions advise cold packs on the face in roughly 20-minute intervals during the first 24 to 48 hours to limit swelling, then switching to warm compresses. Starting heat right away encourages swelling, and waiting until day three to use cold misses the window when it helps most.

Sources: Boston Children's Hospital — Oral and maxillofacial surgery: wisdom teeth care — Swelling; Harvard Dental Center — Periodontal surgery post-operative instructions — Swelling; smoking

Correct answer: B. Smoking

Dry socket is more common in people who smoke, which is why patients are told to avoid smoking after extractions. Brushing the other teeth carefully, drinking cool water and eating soft foods are all normal post-extraction instructions, not risk factors.

Sources: Cork University Dental School & Hospital — Wisdom teeth patient information — Dry socket; Harvard Dental Center — Periodontal surgery post-operative instructions — Swelling; smoking

Correct answer: A. First trimester of pregnancy

The AAPD lists conditions that may contraindicate nitrous oxide/oxygen, including the first trimester of pregnancy, chronic obstructive pulmonary disease, a current upper respiratory infection or blocked nasal breathing, recent middle ear disturbance, recent ear, nose or throat surgery and untreated vitamin B12 deficiency. Mild dental anxiety is a reason nitrous is used, and a healed joint replacement or braces are not on the list.

Source: AAPD — Use of Nitrous Oxide for Pediatric Dental Patients (Reference Manual 2025) — Recommendations

Correct answer: A. Nausea and vomiting

The AAPD reports that nausea and vomiting are the most common adverse effects, occurring in roughly 0.5 to 1.2 percent of patients. Other side effects include oversedation, sweating, dysphoria, restlessness and headache. The AAPD adds that nitrous oxide should not routinely exceed 50 percent. Seizures, severe allergy and permanent hearing loss are not listed among its common effects.

Source: AAPD — Use of Nitrous Oxide for Pediatric Dental Patients (Reference Manual 2025) — General considerations

Correct answer: C. At least 30% oxygen

AAPD guidance says the delivery system must be able to deliver 100 percent oxygen and never less than 30 percent oxygen. It must also have a fail-safe that shuts off nitrous oxide if oxygen flow drops below a set minimum. Lower oxygen percentages risk hypoxia, and monitoring does not replace the equipment safeguard.

Source: AAPD — Use of Nitrous Oxide for Pediatric Dental Patients (Reference Manual 2025) — Facilities/personnel/equipment

Correct answer: D. A fitted hood and breathing through the nose

The AAPD says a fitted nasal hood should be selected and that success depends on the patient accepting the hood and breathing through the nose. Mouth breathing and frequent talking reduce the amount of gas the patient inhales, and a loose hood lets gas escape into the room.

Source: AAPD — Use of Nitrous Oxide for Pediatric Dental Patients (Reference Manual 2025) — Technique of N2O/O2 administration

Correct answer: B. Plaque and extrinsic stain from the enamel surfaces

Coronal polishing removes plaque and stain from enamel surfaces and is done after hard deposits are removed. Calculus is removed with hand or ultrasonic instruments, not with a rubber cup and paste. Polishing cannot reach intrinsic stains within the tooth or treat decay.

Source: Dondiego & Finnerty — Factors in Coronal Polishing, Inside Dental Assisting (2012) — Fundamentals of Coronal Polishing

Source link currently unavailable; the original citation is retained.

Correct answer: B. It stains plaque so it can be seen

Disclosing agents stain dental biofilm so it is visible, which shows where polishing is needed and makes them useful for patient education; some two-tone agents show older biofilm in one color and newer biofilm in another. Coronal polishing protocols list disclosing before polishing. Disclosing agents do not remove stain, harden enamel or numb tissue.

Sources: DentistryIQ — Disclosing solution agents (2024); NSCC Dental Skills Manual (CC BY 4.0) — 2.29 Coronal Polishing — Procedure checklist

Correct answer: C. Molar pits and fissures, including noncavitated lesions

The 2016 ADA/AAPD guideline found sealants effective for preventing and arresting pit-and-fissure occlusal caries on primary and permanent molars in children and adolescents, and noted they can slow the progression of noncavitated lesions. Cavitated lesions generally need restoration, and sealants are for pits and fissures, not smooth proximal surfaces.

Source: ADA Oral Health Topics — Dental Sealants — Evidence

Correct answer: D. Check retention with an explorer, then check the occlusion

After curing, the sealant is evaluated with an explorer for retention, voids and flaws, and the occlusion is checked with articulating paper so the sealant does not interfere with the bite. Skipping the check can leave a loose or high sealant, and re-etching or coarse polishing serve no purpose at this step.

Source: Dentalcare CE673 — Step Eight: Evaluate the Sealant

Correct answer: C. 2.26% fluoride (22,600 ppm)

The ADA describes sodium fluoride varnish as containing 2.26% fluoride, or 22,600 parts per million, which is the 5% sodium fluoride varnish used in offices. It is a high-concentration, professionally applied product, which is why it is applied in a thin layer to dried teeth.

Source: ADA Oral Health Topics — Fluoride: Topical and Systemic Supplements — Professionally applied: fluoride varnish

Correct answer: D. Removal of plaque, calculus and stains from the teeth

The CDT descriptor for prophylaxis (D1110) is the removal of plaque, calculus and stains from the tooth structures (and, in the current wording, implants) to control local irritational factors. Coronal polishing alone is only one part of that, scaling and root planing is a separate periodontal procedure, and sealants and varnish have their own codes. Which team members may perform each part depends on state law.

Source: RDH Magazine — Are D1110/D1120 the proper CDT codes? (July 1, 2025) — D1110 descriptor

Correct answer: B. Once set, temperature changes can't return it to a fluid

Alginate sets by a chemical reaction, so once it gels it cannot be returned to a fluid by changing temperature. Agar is the reversible hydrocolloid: it turns to liquid when heated and gels when cooled, and can cycle back and forth. Alginate does set in the mouth, and it is a different material from agar.

Sources: StatPearls — Dental Alginate Impressions (updated 5/30/2023) — Introduction; Anatomy and Physiology; Onwubu & Okonkwo — Hydrocolloids in Dentistry: A Review (IntechOpen, 2021) — Sections 1.1, 1.2.1, 1.2.2

Correct answer: B. Break the seal and remove it with a single quick snap

StatPearls describes removing a set alginate impression with a quick snap that breaks the seal between the tissues and the tray. Alginate has low tear strength, and slow rocking or one-sided removal stretches and tears it in undercuts. Leaving it in longer than needed adds discomfort without improving accuracy.

Source: StatPearls — Dental Alginate Impressions (updated 5/30/2023) — Impression Taking; Setting Mechanism

Correct answer: D. Polyvinyl siloxane

Addition silicone (PVS) is very dimensionally stable; manufacturers state it shows almost no change over long periods and can be poured later and more than once. Some products release hydrogen gas at first, so follow the label on how soon to pour. Alginate shrinks quickly and should be poured right away, and condensation silicone shrinks on standing and should be poured within about an hour. Agar is also a hydrocolloid that must be poured promptly.

Sources: 3M Imprint 4 Preliminary VPS — technical product sheet — Dimensional stability; pouring; Al-Khafaji — Dental Materials Lecture 6: Elastomeric impression materials — pp. 5–6

Correct answer: B. Utility wax

Utility wax is soft and pliable at room temperature and is used to extend or adjust impression tray borders. Boxing wax is used to wall in an impression before a cast is poured, and inlay and sticky waxes have other laboratory jobs.

Source: Al-Khafaji — Dental Materials Lecture 8: Waxes — pp. 3–4 (boxing and utility wax)

Correct answer: C. It bonds chemically to enamel and dentin and releases fluoride

Glass ionomer forms an ionic (chemical) bond with calcium in enamel and dentin and releases fluoride, both in an early burst and slowly over time. That fluoride release is why it is chosen for higher-risk patients. It is not the strongest option for large load-bearing fillings, and conventional glass ionomer sets by an acid-base reaction, not a curing light.

Source: StatPearls — Glass Ionomer Cement (updated 3/4/2024) — Mechanism of Bonding; Fluoride Release

Correct answer: C. On a cool glass slab, adding powder in small portions

Zinc phosphate's setting reaction is exothermic. Manufacturers direct mixing on a cool glass slab and adding powder in small fractions, which spreads out the heat and extends working time. A warm slab or dumping in all the powder speeds the set and shortens working time, and a paper pad does not absorb heat the way a cool glass slab does.

Sources: Prevest DenPro — Zinc phosphate cement instructions for use — Mixing directions; University of Baghdad College of Dentistry — Cement and Base Materials (2023) — p. 12

Correct answer: B. Stimulate the pulp to form reparative dentin

Calcium hydroxide stimulates odontoblasts to form secondary (reparative) dentin and can form a dentin bridge over a pulp exposure, which is why it is used for direct and indirect pulp capping. It does not bond restorations, its purpose is not fluoride release, and margins are sealed by the restorative material, not the liner.

Sources: University of Baghdad College of Dentistry — Cement and Base Materials (2023) — p. 14; Dentsply Dycal (calcium hydroxide) directions for use — Indications

Correct answer: D. To protect the pulp from heat conducted through the metal

A traditional base sits beneath a metallic restoration to give thermal, mechanical and chemical protection to the pulp, because metal conducts temperature changes. A base does not bond amalgam, whiten teeth or speed the set. Current thinking is that not every metallic restoration needs a base; it is mainly considered for deep preparations.

Source: Arandi & Rabi — Cavity Bases Revisited, Clin Cosmet Investig Dent 2020;12:305–312 — Definition of a Base; Bases Under Amalgam

Correct answer: C. Slightly moist, not dried out

Etching removes minerals from dentin and leaves a network of collagen fibers. If the dentin is air-dried, that collagen collapses and blocks the adhesive from penetrating; kept moist, it stays open so the adhesive can infiltrate. Peroxide and fluoride varnish are not part of the bonding sequence and can interfere with it.

Source: Munksgaard — Acta Odontologica Scandinavica 2002;60:60–64 (wet vs dry dentin bonding) — Introduction; Discussion

Correct answer: A. Cover it to protect it from the operatory light

Light-cured composite can start to set from strong ambient or operatory light. Manufacturer instructions say dispensed material not used right away should be protected from light and the syringe capped immediately. Light speeds setting rather than keeping it soft, and mixing set and fresh material does not restore working time.

Source: 3M Filtek P60 — instructions for use — Directions for direct restorations, steps 5 and 6.3

Correct answer: D. After it sets, at least 45 minutes for Type III

Separating a cast too early can fracture teeth or distort the model. University of Iowa dental lab guidance says to wait at least 45 minutes after pouring before removing a Type III stone cast. Fast-set stones exist, so always follow the specific product's timing. Warmth means the setting reaction is still under way, not that it is finished.

Source: University of Iowa College of Dentistry — Alginate impressions and diagnostic casts (lab slides) — Tips for working with gypsum; Type III stone

Correct answer: D. A reinforced zinc oxide–eugenol material

IRM stands for intermediate restorative material. The manufacturer describes it as a polymer-reinforced zinc oxide–eugenol material indicated for intermediate (temporary, less than a year) fillings. It is not a composite, glass ionomer or amalgam.

Sources: Dentsply IRM Caps — instructions for use (2019) — Sections 1, 1.2, 1.3; DANB — GC Exam Outline and References (effective 07/01/2022) — Acronyms, p. 8 (IRM)

Correct answer: A. A medicated dressing, often zinc oxide–eugenol based

StatPearls describes management of alveolar osteitis as irrigation of the socket plus placement of a medicated dressing, commonly zinc oxide–eugenol based, to relieve pain. Curettage is not recommended. Closing the socket with sutures or leaving dry gauze inside it are not standard treatment.

Source: StatPearls — Alveolar Osteitis (updated 5/29/2023) — Treatment / Management

Correct answer: C. Coarse, then medium, then fine, then superfine

Manufacturer instructions start with coarse discs to remove excess material, move to medium for contouring and fine to prepare the surface, then finish with superfine for a high gloss. Each finer abrasive removes the scratches left by the coarser one, so reversing the order leaves the surface rough.

Source: 3M — Finishing & Polishing Guide (Sof-Lex discs) — pp. 1–2

Correct answer: A. Ventilate, avoid flames and expect it to get hot as it sets

The liquid (methyl methacrylate monomer) is flammable, and its vapors can irritate the eyes and skin and cause headaches, so the safety data sheet calls for ventilation and keeping it away from ignition sources. Self-cure acrylic also sets with a strongly exothermic reaction and can get quite hot. An open bottle and bare-hand contact increase exposure.

Sources: Kerr Formatray Liquid (methyl methacrylate) — safety data sheet — Sections 4, 6, 9; Schiavetti et al. — Control and reduction of heat in self-curing acrylic resins, Oral & Implantology 2009 — Introduction; Table 1