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RDA (Other exams) practice questions

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Question 1Infection Control and Safety Practices

A dental assistant's hands are not visibly soiled but have just been in contact with a patient's saliva. Which hand hygiene method is appropriate?

  1. Rub with an alcohol-based hand rub until the hands are dry Correct answer.
  2. Wash with antimicrobial soap and water for two full minutes
  3. Wipe with a disinfectant towelette made for operatory surfaces
  4. Rinse with water only and dry with a paper towel

Explanation

An alcohol-based hand rub is acceptable whenever hands are not visibly soiled or contaminated with blood or other body fluids, and it should be rubbed in until dry. Soap and water is reserved for visibly soiled hands or exposure to spore-forming organisms.

Question 2Infection Control and Safety Practices

Which gloves are worn when manually cleaning contaminated instruments after a procedure?

  1. Heavy-duty utility gloves Correct answer.
  2. Sterile surgical gloves
  3. Single-use examination gloves
  4. Thin vinyl overgloves

Explanation

Utility gloves are puncture-resistant and reusable, and they are intended for instrument cleanup, decontamination, and handling of chemicals. Examination and surgical gloves are patient-care items and are not designed to resist punctures from sharp instruments.

Question 3Infection Control and Safety Practices

In the recommended sequence for donning personal protective equipment, which item is applied last?

  1. Gown or protective clothing
  2. Treatment gloves Correct answer.
  3. Protective eyewear
  4. Face mask

Explanation

PPE is donned from the cleanest to the most contaminated: gown first, then mask or respirator, then eyewear, and gloves last so that the gloved hands never contaminate the other items.

Question 4Infection Control and Safety Practices

Which sterilization method is used most often in dental offices?

  1. Ethylene oxide gas
  2. Steam autoclave Correct answer.
  3. Dry heat oven
  4. Chemical vapor sterilizer

Explanation

Steam under pressure (the autoclave) is fast, economical, and safe for most metal and heat-tolerant instruments, which is why it is the most common method in dentistry.

Question 5Infection Control and Safety Practices

How often should a steam autoclave be monitored with a biological spore test?

  1. After every individual load
  2. At least once each week Correct answer.
  3. Once each month
  4. Once every six months

Explanation

Biological monitoring is the most reliable check that a sterilizer is actually killing microorganisms, and it should be performed at least weekly, with every load containing implants.

Question 6Infection Control and Safety Practices

At what point should a sharps container be closed and replaced?

  1. When the contents reach the very top of the container
  2. Only at the end of each working day regardless of contents
  3. When it is about three-quarters full Correct answer.
  4. When it is completely full and cannot be packed further

Explanation

Containers must be closed and replaced before they are overfilled, because a container filled to the top invites overflow and accidental sticks when items are added or the lid is secured.

Question 7Infection Control and Safety Practices

Which of the following is classified as other potentially infectious material (OPIM) in dentistry?

  1. Sweat from the patient's forehead
  2. Nasal secretions from a sneeze
  3. Urine collected in a specimen cup
  4. Saliva during a dental procedure Correct answer.

Explanation

OPIM includes blood, semen, vaginal secretions, and body fluids such as saliva in dental procedures, along with any fluid visibly contaminated with blood.

Question 8Infection Control and Safety Practices

Why is protective eyewear placed on the patient before a procedure that may create spatter?

  1. It keeps the patient's eyes closed during treatment
  2. It prevents the patient from inhaling nitrous oxide
  3. It protects the patient's eyes from splatter and debris Correct answer.
  4. It replaces the need for a rubber dam during drilling

Explanation

Patients as well as staff are at risk from flying debris, droplets, and aerosols generated during dental procedures, so patient eyewear is part of routine PPE.

Question 9Infection Control and Safety Practices

A dental assistant sustains a needlestick from a contaminated needle. What should be done first?

  1. Scrub the wound with an alcohol-based disinfectant
  2. Apply a topical antibiotic and continue the procedure
  3. Squeeze the site firmly to express blood, then cover it
  4. Wash the puncture site with soap and water Correct answer.

Explanation

Immediate care after a percutaneous exposure is to wash the site with soap and water and flush mucous membranes with water. The exposure is then reported so the source patient can be evaluated and post-exposure prophylaxis considered.

Question 10Infection Control and Safety Practices

Which technique is correct when removing contaminated treatment gloves?

  1. Remove both gloves together by pulling them off from the wrist
  2. Pull each glove off by the fingertips of the other gloved hand, touching only the outside
  3. Peel the gloves off by the cuff while touching the outside with the bare hand
  4. Peel off one glove by its outside, then the second from the inside Correct answer.

Explanation

The first glove is peeled off by grasping its outer surface so the bare hand never contacts it, and the second is removed by sliding ungloved fingers under the cuff, turning it inside out. This keeps contaminated surfaces contained inside the inverted glove.

Question 11Infection Control and Safety Practices

An external chemical indicator on an instrument pack changes color after the autoclave cycle. What does this confirm?

  1. The pack was exposed to the sterilization process Correct answer.
  2. The biological spore test for that load has passed
  3. The instruments inside are sterile and ready to use
  4. The autoclave reached the correct temperature for the full time

Explanation

External chemical indicators show only that the package was processed and that the sterilizing agent reached the outside of the pack. They do not prove that sterilization conditions were met inside, which requires internal indicators and biological monitoring.

Question 12Infection Control and Safety Practices

A surgical mask becomes damp during a long appointment. What is the appropriate action?

  1. Cover it with a second dry mask
  2. Replace it with a new mask before continuing Correct answer.
  3. Continue wearing it until the appointment is over
  4. Turn the mask around and continue the procedure

Explanation

Moisture compromises the filtration barrier of a mask, so a damp or soiled mask must be replaced. Masks are also changed between patients.

Question 13Infection Control and Safety Practices

Before pouring a stone model, how should an elastomeric impression be handled?

  1. Wipe it with a dry gauze and pour immediately
  2. Rinse and disinfect it per the manufacturer's directions Correct answer.
  3. Soak it in glutaraldehyde for ten hours
  4. Place it in the autoclave for a short cycle

Explanation

Impressions carry saliva and blood and must be rinsed and disinfected with a product compatible with the impression material before they leave the operatory or enter the laboratory. Manufacturer directions must be followed to avoid distortion.

Question 14Infection Control and Safety Practices

Which surfaces in the operatory are best managed with fluid-resistant barriers?

  1. The floor beneath the operator's stool
  2. The inside chamber of the autoclave
  3. Light handles, bracket tray, and chair switches Correct answer.
  4. Wall surfaces and the ceiling of the treatment room

Explanation

Barriers are used on clinical contact surfaces that are touched during care and are difficult to disinfect, such as handles, switches, and tray tops. They are removed and replaced between patients.

Question 15Infection Control and Safety Practices

How should dental unit waterlines be managed between patients?

  1. They are flushed only at the beginning of the day
  2. They are flushed for 20 to 30 seconds Correct answer.
  3. They are drained and refilled after each patient
  4. They require no flushing if a barrier was used

Explanation

Running the waterlines for roughly 20 to 30 seconds between patients physically flushes out organisms and material that may have been drawn back into the line. A longer flush is also performed at the start of the day.

Question 16Infection Control and Safety Practices

A patient reports a severe latex allergy. Which action is most appropriate?

  1. Ask the patient to bring their own latex gloves
  2. Use latex gloves but double them for protection
  3. Schedule as the first patient with latex-free supplies Correct answer.
  4. Powder the gloves before donning to reduce reaction

Explanation

A latex-allergic patient should be seen in an environment cleared of latex, often as the first appointment of the day before airborne latex proteins accumulate. All staff should wear non-latex gloves and latex-free items should be used.

Question 17Infection Control and Safety Practices

How should an ultrasonic cleaning unit be operated?

  1. Only after the solution has been heated to boiling
  2. With the lid open so instruments can be watched
  3. Empty of solution while instruments are loaded
  4. With the lid closed to contain aerosols Correct answer.

Explanation

Ultrasonic cleaning generates aerosols from contaminated solution, so the lid stays closed during operation. The solution is changed at least daily or when visibly soiled.

Question 18Infection Control and Safety Practices

Under the bloodborne pathogens standard, what must an employer offer to employees with occupational exposure?

  1. Hepatitis B vaccination at no cost Correct answer.
  2. Quarterly HIV testing of all staff
  3. Annual antibiotic prophylaxis
  4. Free prescription safety eyewear

Explanation

Employers must offer the hepatitis B vaccine, free of charge and within a set period after assignment, to every employee with occupational exposure. Employees may decline, but the declination must be documented.

Question 19Infection Control and Safety Practices

How should an extracted tooth that contains no amalgam be disposed of?

  1. Flushed down the sink with running water
  2. In a labeled biohazard waste container Correct answer.
  3. In the sharps container with used needles
  4. In the regular trash in a sealed paper bag

Explanation

Extracted teeth are blood-contaminated items and are discarded as regulated medical waste in a labeled or color-coded biohazard container. Teeth containing amalgam are handled separately because of mercury content.

Question 20Infection Control and Safety Practices

Which product is required to clean a blood spill on a countertop?

  1. A quaternary ammonium product labeled as a deodorizer
  2. An EPA-registered tuberculocidal hospital disinfectant Correct answer.
  3. A spray of 70 percent isopropyl alcohol
  4. A non-detergent soap solution

Explanation

Surfaces contaminated with blood must first be cleaned of visible material and then treated with a disinfectant that carries a tuberculocidal claim, or with a freshly prepared dilution of household bleach.

Question 21Infection Control and Safety Practices

What is the recommended maximum heterotrophic bacterial count for dental unit treatment water?

  1. 50 CFU/mL
  2. 200 CFU/mL
  3. 500 CFU/mL Correct answer.
  4. 2,000 CFU/mL

Explanation

The CDC and ADA recommend that dental unit water used in treatment contain no more than 500 colony-forming units per milliliter, matching the EPA drinking water standard.

Question 22Infection Control and Safety Practices

Why are Geobacillus stearothermophilus spores used to monitor steam sterilizers?

  1. They grow only on dry surfaces inside the chamber
  2. They are the organism that most often contaminates waterlines
  3. They change color when the chamber pressure drops
  4. Their spores resist heat more than most pathogens do Correct answer.

Explanation

Bacterial spores are the most resistant form of microbial life, so a sterilizer that kills the test spores is presumed to have killed the less resistant organisms present on instruments.

Question 23Infection Control and Safety Practices

A dental assistant has a percutaneous exposure to blood from a patient with unknown HIV status. When should she seek evaluation for post-exposure prophylaxis?

  1. Within two weeks of the exposure
  2. After the source patient's test results return
  3. Immediately, ideally within hours of exposure Correct answer.
  4. Only if symptoms develop within 72 hours

Explanation

HIV post-exposure prophylaxis is most effective when started as soon as possible after exposure, ideally within hours. Evaluation should not be delayed while waiting for source patient testing to be completed.

Question 24Infection Control and Safety Practices

How often must an employer's written exposure control plan be reviewed and updated?

  1. Only after an employee injury
  2. At least once a year Correct answer.
  3. Whenever a new employee is hired
  4. Every five years

Explanation

The bloodborne pathogens standard requires the exposure control plan to be reviewed and updated at least annually and whenever tasks, procedures, or positions change.

Question 25Infection Control and Safety Practices

Which practice is prohibited for clinical dental personnel?

  1. Wearing a plain ring under treatment gloves
  2. Wearing artificial nails or nail extenders Correct answer.
  3. Using a facility-provided antimicrobial soap
  4. Applying lotion after hand hygiene is complete

Explanation

Artificial nails and extenders harbor microorganisms and are associated with outbreaks, so they are prohibited for staff who perform patient care or handle sterile supplies. Natural nails are kept short and clean.

Question 26Infection Control and Safety Practices

A dental assistant's hands are visibly contaminated with blood after removing torn gloves. What is the appropriate hand hygiene action?

  1. Rub hands with an alcohol-based hand rub
  2. Wash hands with soap and water Correct answer.
  3. Rinse hands with water only
  4. Wipe hands with an antiseptic towelette

Explanation

Soap and water are required when hands are visibly soiled or contaminated with blood or other body fluids. Alcohol-based hand rubs are intended for hands that are not visibly dirty because organic material can reduce their effectiveness.

Question 27Infection Control and Safety Practices

Which glove type is intended for cleaning contaminated instruments and environmental surfaces?

  1. Nitrile examination gloves
  2. Heavy-duty utility gloves Correct answer.
  3. Vinyl examination gloves
  4. Sterile surgical gloves

Explanation

Heavy-duty utility gloves are designed to resist punctures and chemicals during cleaning and disinfection tasks. Examination and surgical gloves are intended for patient care rather than handling sharp contaminated instruments.

Question 28Infection Control and Safety Practices

Protective eyewear worn during patient care should include which feature?

  1. A tinted lens
  2. A built-in magnifier
  3. Side shields Correct answer.
  4. An anti-fog coating

Explanation

Eyewear must protect the eyes from splashes and spatter coming from the front and sides, so side shields are required. Tinted lenses, magnifiers, and anti-fog coatings are optional features and do not provide the required lateral protection.

Question 29Infection Control and Safety Practices

Sterile gloves are most appropriate for which situation?

  1. Applying fluoride varnish
  2. A routine prophylaxis
  3. A surgical extraction Correct answer.
  4. Taking a radiograph

Explanation

Sterile gloves are indicated for invasive or surgical procedures where the goal is to prevent contamination of the surgical site. Routine nonsurgical procedures generally require examination gloves rather than sterile gloves.

Question 30Infection Control and Safety Practices

Which item is intended for single use and should be discarded after one patient?

  1. Saliva ejector tip Correct answer.
  2. Autoclavable impression tray
  3. Stainless steel mouth mirror
  4. Metal explorer

Explanation

Saliva ejector tips are disposable items and cannot be reliably cleaned or sterilized for reuse. Metal mirrors, explorers, and autoclavable trays are reusable after proper cleaning and sterilization.

Question 31Infection Control and Safety Practices

Which feature is required for a sharps container used in a dental office?

  1. Puncture-resistant walls Correct answer.
  2. A screw-on lid
  3. A minimum 5-gallon capacity
  4. Transparent sides for visibility

Explanation

Sharps containers must be closable, leak-resistant, puncture-resistant, and labeled with a biohazard warning. Transparency, screw-on lids, and a specific large capacity are not required features.

Question 32Infection Control and Safety Practices

If a needle must be recapped, which technique should be used?

  1. Recapping is never permitted
  2. Forceps to hold the cap
  3. One-handed scoop method Correct answer.
  4. Two hands while holding the cap on the counter

Explanation

The one-handed scoop method allows the needle to be recapped without bringing the other hand near the sharp. Recapping should be avoided whenever possible, but the scoop technique is the accepted method when it is necessary.

Question 33Infection Control and Safety Practices

After removing examination gloves following patient care, what should be done?

  1. Put on a new pair of gloves
  2. Wipe hands with a paper towel
  3. Apply alcohol hand rub only if hands feel sticky
  4. Wash hands with soap and water Correct answer.

Explanation

Hands must be washed after glove removal because gloves may have small defects or may be removed with contamination. Hand hygiene is required even when gloves were worn for the entire procedure.

Question 34Infection Control and Safety Practices

How soon after initial assignment must an employer offer the hepatitis B vaccine to an employee with occupational exposure risk?

  1. Within 90 days
  2. Within 30 calendar days
  3. Within 10 working days Correct answer.
  4. Within 24 hours

Explanation

The bloodborne pathogens standard requires the hepatitis B vaccine to be offered within 10 working days of initial assignment to employees with occupational exposure. The employee may decline but must sign a declination form.

Question 35Infection Control and Safety Practices

How often should a steam sterilizer be monitored with a biological indicator?

  1. Only when a new sterilizer is installed
  2. Once per month
  3. At least weekly Correct answer.
  4. After every load

Explanation

Biological indicators are used at least weekly to verify that the sterilizer is killing resistant bacterial spores. More frequent monitoring may be required by manufacturer instructions or when processing implants.

Question 36Infection Control and Safety Practices

A biological indicator test from a steam sterilizer is positive. What is the appropriate response?

  1. Remove the sterilizer from service and recall items Correct answer.
  2. Increase the sterilization cycle temperature by 5 degrees and retest
  3. Repeat the biological test on the same load and continue processing patients
  4. Discard only the instruments that were in the positive-test load

Explanation

A positive biological indicator means the cycle did not achieve sterilization. The sterilizer must be removed from service, and all items processed since the last negative biological indicator must be recalled and reprocessed. The cause should be investigated and the sterilizer retested before use resumes.

Question 37Infection Control and Safety Practices

Which test is used daily to verify air removal in a pre-vacuum steam sterilizer?

  1. Spore strip test
  2. Bowie-Dick test Correct answer.
  3. Chemical indicator strip
  4. Enzyme-based protein test

Explanation

The Bowie-Dick test is run daily on pre-vacuum sterilizers to confirm that air is being removed and steam can penetrate the load. Biological indicators verify spore kill, while chemical indicators show that sterilization conditions were met.

Question 38Infection Control and Safety Practices

Which method is appropriate for a heat-sensitive item that cannot be steam sterilized?

  1. Dry heat sterilization in an oven
  2. Wiping with 70% isopropyl alcohol
  3. Exposure in an ultraviolet light cabinet
  4. Chemical sterilant immersion Correct answer.

Explanation

Heat-sensitive items can be processed by immersion in a chemical sterilant using the manufacturer's labeled concentration and contact time. The contact time determines whether high-level disinfection or sterilization is achieved.

Question 39Infection Control and Safety Practices

Which water should be used in a steam sterilizer reservoir?

  1. Tap water
  2. Distilled water Correct answer.
  3. Deionized water with saline
  4. Sterile saline

Explanation

Distilled water is recommended to prevent mineral deposits that can damage the sterilizer and interfere with steam quality. Tap water and saline solutions may leave scale or cause corrosion.

Question 40Infection Control and Safety Practices

What should be done to hinged instruments before they are placed in a sterilization pouch?

  1. Close and lock the hinges
  2. Open the hinges Correct answer.
  3. Wrap them in a closed cassette without a pouch
  4. Oil the hinges heavily

Explanation

Hinged instruments should be opened so steam can contact all surfaces, including the box lock and hinge area. Instruments should not be locked closed or heavily oiled before sterilization.

Question 41Infection Control and Safety Practices

Which statement about dental handpieces is correct?

  1. They need sterilization only after visible blood
  2. They can be wiped with alcohol between patients
  3. They must be heat sterilized between patients Correct answer.
  4. They require only high-level disinfection

Explanation

Handpieces that contact oral tissues must be cleaned and heat sterilized between patients. Wiping with alcohol or high-level disinfection alone does not provide the required level of processing for these devices.

Question 42Infection Control and Safety Practices

Which sequence correctly describes removal of personal protective equipment after patient care?

  1. Gown, then gloves, then mask, then eyewear
  2. Eyewear, then mask, then gloves, then gown
  3. Mask, then gloves, then gown, then eyewear
  4. Gloves, eyewear, gown, mask Correct answer.

Explanation

The generally accepted order is to remove gloves first, then eyewear, then the gown, and finally the mask or respirator. The mask is removed last because it protects the mouth and nose from contamination during removal of the other items.

Question 43Infection Control and Safety Practices

What is the primary infection-control benefit of using a rubber dam during restorative treatment?

  1. It replaces the need for a face mask
  2. It reduces microorganisms in aerosols Correct answer.
  3. It sterilizes the operative field
  4. It eliminates the need for high-volume evacuation

Explanation

A rubber dam limits the spread of saliva and oral microorganisms into the air during treatment. It does not sterilize the field, eliminate the need for high-volume evacuation, or replace personal protective equipment.

Question 44Infection Control and Safety Practices

An intermediate-level disinfectant used on environmental surfaces in dentistry must carry a label claim against which organism?

  1. Mycobacterium tuberculosis Correct answer.
  2. Bacterial spores
  3. Hepatitis A virus only
  4. Prions

Explanation

Intermediate-level disinfectants must be tuberculocidal, meaning they can inactivate Mycobacterium tuberculosis. This claim serves as a benchmark for activity against a broad range of organisms.

Question 45Infection Control and Safety Practices

Which item is classified as regulated medical waste?

  1. A used paper cup
  2. A radiograph duplicate that was never used
  3. Gauze saturated with blood Correct answer.
  4. An empty saliva ejector

Explanation

Regulated medical waste includes items that are saturated or dripping with blood or other potentially infectious material. Empty saliva ejectors, paper cups, and unused radiograph duplicates are not regulated medical waste.

Question 46Infection Control and Safety Practices

A small mercury spill occurs in the operatory. Which cleanup method is appropriate?

  1. A standard vacuum cleaner
  2. A mop with hot water
  3. A mercury spill kit with sulfur powder Correct answer.
  4. Compressed air to blow it into a container

Explanation

Mercury spills should be cleaned with a dedicated spill kit; sulfur powder or amalgam alloy helps convert mercury into a less volatile form for collection. Vacuuming, heating, or blowing mercury spreads toxic vapor.

Question 47Infection Control and Safety Practices

How long should the eyes be flushed at an eyewash station after a chemical splash?

  1. Continue flushing for 10 seconds
  2. Rinse for 1 minute
  3. Flush for 5 minutes
  4. At least 15 minutes Correct answer.

Explanation

Chemical splashes to the eye require immediate flushing with water for at least 15 minutes. The eyelids should be held open so the entire eye surface is rinsed.

Question 48Infection Control and Safety Practices

Which fingernail practice is acceptable for a dental assistant providing direct patient care?

  1. Artificial nails
  2. Short natural nails Correct answer.
  3. Nail polish that is chipped
  4. Nail extensions

Explanation

Clinical personnel should keep nails short and natural because artificial nails and long nails can harbor microorganisms and interfere with glove integrity. Chipped polish is also discouraged because it can trap debris.

Question 49Infection Control and Safety Practices

Which respiratory protection is appropriate when treating a patient with suspected active tuberculosis?

  1. A cloth face covering
  2. A face shield
  3. An N95 filtering facepiece respirator Correct answer.
  4. A standard surgical mask

Explanation

Suspected or confirmed active tuberculosis requires airborne precautions, which include an N95 respirator for the clinician. Surgical masks and cloth coverings do not seal tightly enough to filter airborne droplet nuclei.

Question 50Infection Control and Safety Practices

Who is responsible for providing personal protective equipment at no cost to dental employees?

  1. The patient
  2. The employer Correct answer.
  3. The dental supplier
  4. The employee

Explanation

Under the bloodborne pathogens standard, the employer must provide appropriate personal protective equipment at no cost to employees. Employees are not expected to purchase their own required PPE.