Free Dental Hygiene Licensure Objective Structured Clinical Examination Practice Questions

Sample Practice Questions

Try these 10 sample questions from the Dental Hygiene Licensure Objective Structured Clinical Examination practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1During a comprehensive periodontal charting, a dental hygienist finds 2 mm of interdental clinical attachment loss on the mesial of tooth 3 and on the distal of tooth 14, with no other attachment loss and no non-periodontal explanation. Under the 2017 World Workshop case definition, how should this patient be categorized?

   1. A. As an undetermined case, because radiographs must show bone loss before any diagnosis
   2. B. As a gingivitis case, because the attachment loss at each of the sites is less than 3 mm
   3. C. As a periodontal health case, because only two teeth in the dentition show attachment loss
   4. D. As a periodontitis case, because interdental CAL is found at two or more non-adjacent teeth

   Answer: D

   Explanation: The EFP guidance note on the World Workshop case definition states that a patient is a periodontitis case when "Interdental CAL is detectable at ≥2 non-adjacent teeth" (or buccal/oral CAL of 3 mm or more with pocketing above 3 mm is detectable at 2 or more teeth), provided the CAL cannot be ascribed to non-periodontal causes.

   Reference: EFP World Workshop guidance note: Periodontitis (Sanz and Tonetti) — Clinical definition of periodontitis, periodontitis case criteria

2. 2After completing root planing, a dental hygienist sorts the instruments used at the chair. Under the CDC patient-care item categories used in dental settings, which category applies to the periodontal curets and scalers that were used subgingivally?

   1. A. Semicritical
   2. B. Critical
   3. C. Noncritical
   4. D. Clinical contact surface

   Answer: B

   Explanation: CDC states: "Critical items, such as surgical instruments and periodontal scalers, are those used to penetrate soft tissue or bone." It adds that they "should always be sterilized using heat." Semicritical items (e.g., mouth mirrors) contact mucous membranes only, noncritical items contact intact skin only, and clinical contact surfaces are environmental surfaces, not instruments.

   Reference: Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care — p. 12, Sterilization and Disinfection of Patient-Care Items and Devices

3. 3A 24-year-old patient has 4 mm of clinical attachment loss only on the distal of tooth 18, where an impacted third molar was recently extracted. Under the 2017 World Workshop periodontitis case definition, how should this attachment loss be interpreted?

   1. A. It confirms periodontitis, because any CAL of 4 mm defines a case
   2. B. It is excluded, because it can be ascribed to a non-periodontal cause
   3. C. It confirms stage III periodontitis, because the CAL is at a molar
   4. D. It counts toward the case once radiographs confirm bone loss there

   Answer: B

   Explanation: The EFP guidance note states that the observed CAL must not be ascribable to non-periodontal causes, including "The presence of CAL on the distal aspect of a second molar and associated with malposition or extraction of a third molar".

   Reference: EFP World Workshop guidance note: Periodontitis (Sanz and Tonetti) — Clinical definition of periodontitis, non-periodontal causes of CAL

4. 4A dental hygienist finishes coronal polishing with a reusable, heat-tolerant prophylaxis angle attached to a low-speed handpiece motor. According to CDC, how should the prophylaxis angle and motor be processed before the next patient?

   1. A. Immerse them in a high-level disinfectant for the labeled contact time
   2. B. Wipe them with an intermediate-level EPA-registered disinfectant
   3. C. Clean them and heat-sterilize them before use on the next patient
   4. D. Cover them with an FDA-cleared barrier and wipe them after removal

   Answer: C

   Explanation: CDC states that "Dental handpieces and associated attachments, including low-speed motors and reusable prophylaxis angles, should always be heat sterilized between patients and not high-level or surface disinfected." Their internal surfaces can become contaminated with patient material, so high-level disinfection, surface disinfection, or barrier protection is not sufficient for these attachments.

   Reference: Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care — p. 12, Sterilization and Disinfection of Patient-Care Items and Devices (Note on dental handpieces)

5. 5A periodontitis patient's bleeding on probing drops from 60% to 8% of sites after therapy, while attachment levels are unchanged. According to the World Workshop guidance on periodontitis, what does this change in bleeding on probing do to the patient's initial case definition and severity classification?

   1. A. It downgrades the initial case to gingivitis
   2. B. It lowers the stage by one level of severity
   3. C. It does not change the case definition or severity
   4. D. It removes the periodontitis diagnosis entirely

   Answer: C

   Explanation: The EFP guidance note states that bleeding on probing is important for assessing treatment outcomes and residual risk, but "BOP itself does not change the initial case definition as defined by CAL or change the classification of the severity of periodontitis."

   Reference: EFP World Workshop guidance note: Periodontitis (Sanz and Tonetti) — Clinical definition of periodontitis, role of bleeding on probing

6. 6A practice's digital radiography sensor cannot tolerate heat sterilization or high-level disinfection according to its manufacturer. Per CDC, what is the minimum reprocessing approach for this semicritical sensor between patients?

   1. A. Use an FDA-cleared barrier, then clean and disinfect with an intermediate-level (tuberculocidal) EPA-registered hospital disinfectant
   2. B. Use an FDA-cleared barrier, then discard the barrier and reuse the sensor without any additional cleaning or disinfection step
   3. C. Skip the barrier, then clean and disinfect the sensor with a low-level (HIV and HBV claim) EPA-registered hospital disinfectant
   4. D. Skip the barrier, then wipe the sensor with an alcohol-based hand rub product and allow it to air-dry before the next patient

   Answer: A

   Explanation: CDC states that for a sensor that cannot be heat-sterilized or high-level disinfected, "If the item cannot tolerate these procedures then, at a minimum, protect with an FDA-cleared barrier." It continues: "clean and disinfect with an Environmental Protection Agency (EPA)-registered hospital disinfectant with intermediate-level (i.e., tuberculocidal claim) activity between patients." A barrier alone or a low-level disinfectant does not meet this minimum.

   Reference: Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care — p. 12, Sterilization and Disinfection of Patient-Care Items and Devices (digital radiography sensors)

7. 7A patient has periodontitis with a greatest interdental clinical attachment loss of 4 mm, no tooth loss due to periodontitis, probing depths no greater than 5 mm, and mostly horizontal bone loss. Using the AAP staging chart, which stage applies?

   1. A. Stage I
   2. B. Stage IV
   3. C. Stage III
   4. D. Stage II

   Answer: D

   Explanation: The AAP staging chart lists "Interdental CAL (at site of greatest loss) 1 – 2 mm 3 – 4 mm ≥5 mm ≥5 mm" for Stages I through IV, so 3–4 mm corresponds to Stage II. Stage II complexity is a maximum probing depth of 5 mm or less with mostly horizontal bone loss, and no complexity factor shifts this case higher.

   Reference: AAP Staging and Grading Periodontitis chart — Periodontitis: Staging table, Severity row

8. 8A dental hygienist is packaging a cassette of periodontal instruments for steam sterilization. Which monitoring method does CDC say should be placed with every package to verify that steam has penetrated the package and reached the instruments?

   1. A. A biological spore-test strip placed in the cassette
   2. B. A strip of external indicator tape on the wrap
   3. C. A printout of the cycle's time and temperature
   4. D. A chemical indicator placed inside the package

   Answer: D

   Explanation: CDC states: "A chemical indicator should be used inside every package to verify that the sterilizing agent (e.g., steam) has penetrated the package and reached the instruments inside." Spore tests are run periodically (at least weekly), mechanical printouts monitor the cycle rather than each package interior, and external tape is added only when the internal indicator cannot be seen from outside.

   Reference: Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care — p. 13, Sterilization and Disinfection of Patient-Care Items and Devices (chemical monitoring)

9. 9A new patient's periodontal chart is incomplete because the cementoenamel junctions could not be reliably detected, so clinical attachment loss is not available. Recent diagnostic-quality radiographs are available. According to the AAP staging chart, what should be used to determine the initial stage?

   1. A. Probing depth at the deepest site
   2. B. Radiographic bone loss (RBL)
   3. C. Percentage of sites bleeding
   4. D. Gingival recession at each tooth

   Answer: B

   Explanation: The AAP chart states: "Initial stage should be determined using clinical attachment loss (CAL). If CAL is not available, radiographic bone loss (RBL) should be used."

   Reference: AAP Staging and Grading Periodontitis chart — Periodontitis: Staging, introductory text

10. 10A dental hygiene clinic is reviewing how often its steam sterilizer is challenged with biological indicators. What is the minimum spore-testing frequency recommended by CDC for dental sterilizers?

    1. A. At least monthly
    2. B. At least quarterly
    3. C. At least weekly
    4. D. At least annually

    Answer: C

    Explanation: CDC states: "A spore test should be used at least weekly to monitor sterilizers." Because spore tests are periodic and results are delayed, mechanical and chemical monitoring are also performed with each cycle.

    Reference: Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care — p. 13, Sterilization and Disinfection of Patient-Care Items and Devices (biological monitoring)