California Dental Hygiene Examination
with Practice Questions And Correct
Answers (Verifi
1. A patient presents with generalized severe chronic periodontitis and poorly
controlled type 2 diabetes (HbA1c 9.2%). Which sequence of dental hygiene
interventions best reflects current evidence-based practice for this patient?
A. Immediate full-mouth extraction referral followed by antibiotic prophylaxis
B. Nonsurgical periodontal therapy with quarterly maintenance, combined with medical
referral for glycemic optimization and consideration of adjunctive systemic antibiotics
C. Only supragingival prophylaxis until HbA1c falls below 7%, then reevaluate
D. Prescribe a 10-day course of amoxicillin and metronidazole without mechanical
therapy
Answer: B. Nonsurgical periodontal therapy with quarterly maintenance, combined
with medical referral for glycemic optimization and consideration of adjunctive
systemic antibiotics
Rationale: Current evidence supports nonsurgical periodontal therapy plus frequent
maintenance and medical co-management to improve glycemic control, as bidirectional
relationships exist between diabetes and periodontitis. Systemic antibiotics are adjunctive,
not primary, and should follow mechanical debridement. Delaying subgingival therapy or
using antibiotics alone is inconsistent with guidelines.
Page 1 of 80
,2. Under the California Dental Practice Act, which task may a Registered Dental
Hygienist (RDH) perform without direct supervision but requires a written
prescription from a dentist?
A. Administration of local anesthesia
B. Placement of a temporary restoration
C. Oral prophylaxis on a patient of record
D. Administration of nitrous oxide-oxygen analgesia
Answer: D. Administration of nitrous oxide-oxygen analgesia
Rationale: In California, nitrous oxide-oxygen analgesia may be administered by an RDH
under general supervision (not direct) but requires a written prescription from the treating
dentist. Local anesthesia may be administered under direct supervision; temporary
restorations are not within RDH scope; prophylaxis is a primary RDH function not
requiring a separate prescription.
Page 2 of 80
,3. A patient with a history of infective endocarditis is scheduled for scaling and root
planing. According to the 2021 AHA guidelines, which regimen is appropriate for
antibiotic prophylaxis?
A. Amoxicillin 2 g orally 30-60 minutes before the procedure
B. Clindamycin 600 mg orally 30-60 minutes before the procedure
C. Azithromycin 500 mg orally 1 hour before the procedure
D. No prophylaxis is indicated for scaling and root planing
Answer: A. Amoxicillin 2 g orally 30-60 minutes before the procedure
Rationale: The 2021 AHA guidelines recommend amoxicillin 2 g as first-line prophylaxis
for high-risk cardiac conditions before invasive dental procedures involving manipulation
of gingival tissue. Clindamycin is no longer recommended due to adverse events, and
azithromycin is a second-line alternative only for penicillin allergy. Prophylaxis is
indicated for this patient.
4. A dental hygienist observes a radiolucent lesion at the apex of a mandibular incisor
with a history of trauma. Which advanced imaging modality provides the highest
diagnostic yield for detecting a vertical root fracture?
A. Periapical radiography with paralleling technique
B. Panoramic radiography
C. Cone-beam computed tomography (CBCT) with limited field of view
D. Bitewing radiography
Answer: C. Cone-beam computed tomography (CBCT) with limited field of view
Rationale: CBCT with a limited field of view offers three-dimensional visualization and is
superior for detecting vertical root fractures and associated bone loss compared to 2D
imaging. Periapical and panoramic radiographs often miss fractures due to projection
geometry and superimposition. Bitewings are not indicated for apical pathology.
Page 3 of 80
, 5. Which statement best describes the mechanism of action of chlorhexidine gluconate
when used as an adjunctive chemical plaque control agent?
A. It disrupts bacterial cell membranes and precipitates cytoplasmic contents, exhibiting
substantivity due to binding to oral tissues
B. It inhibits cyclooxygenase-2, reducing gingival inflammation without direct
antibacterial effect
C. It acts as a quaternary ammonium compound that lyses bacteria through osmotic
imbalance
D. It chelates calcium ions, preventing calculus formation but not affecting plaque
biofilm
Answer: A. It disrupts bacterial cell membranes and precipitates cytoplasmic
contents, exhibiting substantivity due to binding to oral tissues
Rationale: Chlorhexidine is a bisbiguanide that disrupts microbial cell membranes and
precipitates cell contents; its cationic nature allows binding to oral tissues, providing
prolonged substantivity. It is not an anti-inflammatory agent, not a quaternary ammonium
compound, and does not primarily chelate calcium.
6. During administration of an inferior alveolar nerve block, the patient reports a
sudden sharp pain and the clinician notes the syringe plunger is difficult to depress.
Which complication is most likely occurring?
A. Intravascular injection into the inferior alveolar artery
B. Needle contact with the mandibular nerve causing paresthesia
C. Needle deflection into the parotid gland
D. Trismus due to medial pterygoid muscle trauma
Answer: B. Needle contact with the mandibular nerve causing paresthesia
Rationale: A sudden sharp pain during injection often indicates needle contact with the
nerve, which can lead to paresthesia. Intravascular injection would present with rapid
onset of systemic symptoms, not difficulty depressing the plunger. Parotid gland
involvement and trismus typically occur from different mechanisms and are not
characterized by sharp pain during injection.
Page 4 of 80
with Practice Questions And Correct
Answers (Verifi
1. A patient presents with generalized severe chronic periodontitis and poorly
controlled type 2 diabetes (HbA1c 9.2%). Which sequence of dental hygiene
interventions best reflects current evidence-based practice for this patient?
A. Immediate full-mouth extraction referral followed by antibiotic prophylaxis
B. Nonsurgical periodontal therapy with quarterly maintenance, combined with medical
referral for glycemic optimization and consideration of adjunctive systemic antibiotics
C. Only supragingival prophylaxis until HbA1c falls below 7%, then reevaluate
D. Prescribe a 10-day course of amoxicillin and metronidazole without mechanical
therapy
Answer: B. Nonsurgical periodontal therapy with quarterly maintenance, combined
with medical referral for glycemic optimization and consideration of adjunctive
systemic antibiotics
Rationale: Current evidence supports nonsurgical periodontal therapy plus frequent
maintenance and medical co-management to improve glycemic control, as bidirectional
relationships exist between diabetes and periodontitis. Systemic antibiotics are adjunctive,
not primary, and should follow mechanical debridement. Delaying subgingival therapy or
using antibiotics alone is inconsistent with guidelines.
Page 1 of 80
,2. Under the California Dental Practice Act, which task may a Registered Dental
Hygienist (RDH) perform without direct supervision but requires a written
prescription from a dentist?
A. Administration of local anesthesia
B. Placement of a temporary restoration
C. Oral prophylaxis on a patient of record
D. Administration of nitrous oxide-oxygen analgesia
Answer: D. Administration of nitrous oxide-oxygen analgesia
Rationale: In California, nitrous oxide-oxygen analgesia may be administered by an RDH
under general supervision (not direct) but requires a written prescription from the treating
dentist. Local anesthesia may be administered under direct supervision; temporary
restorations are not within RDH scope; prophylaxis is a primary RDH function not
requiring a separate prescription.
Page 2 of 80
,3. A patient with a history of infective endocarditis is scheduled for scaling and root
planing. According to the 2021 AHA guidelines, which regimen is appropriate for
antibiotic prophylaxis?
A. Amoxicillin 2 g orally 30-60 minutes before the procedure
B. Clindamycin 600 mg orally 30-60 minutes before the procedure
C. Azithromycin 500 mg orally 1 hour before the procedure
D. No prophylaxis is indicated for scaling and root planing
Answer: A. Amoxicillin 2 g orally 30-60 minutes before the procedure
Rationale: The 2021 AHA guidelines recommend amoxicillin 2 g as first-line prophylaxis
for high-risk cardiac conditions before invasive dental procedures involving manipulation
of gingival tissue. Clindamycin is no longer recommended due to adverse events, and
azithromycin is a second-line alternative only for penicillin allergy. Prophylaxis is
indicated for this patient.
4. A dental hygienist observes a radiolucent lesion at the apex of a mandibular incisor
with a history of trauma. Which advanced imaging modality provides the highest
diagnostic yield for detecting a vertical root fracture?
A. Periapical radiography with paralleling technique
B. Panoramic radiography
C. Cone-beam computed tomography (CBCT) with limited field of view
D. Bitewing radiography
Answer: C. Cone-beam computed tomography (CBCT) with limited field of view
Rationale: CBCT with a limited field of view offers three-dimensional visualization and is
superior for detecting vertical root fractures and associated bone loss compared to 2D
imaging. Periapical and panoramic radiographs often miss fractures due to projection
geometry and superimposition. Bitewings are not indicated for apical pathology.
Page 3 of 80
, 5. Which statement best describes the mechanism of action of chlorhexidine gluconate
when used as an adjunctive chemical plaque control agent?
A. It disrupts bacterial cell membranes and precipitates cytoplasmic contents, exhibiting
substantivity due to binding to oral tissues
B. It inhibits cyclooxygenase-2, reducing gingival inflammation without direct
antibacterial effect
C. It acts as a quaternary ammonium compound that lyses bacteria through osmotic
imbalance
D. It chelates calcium ions, preventing calculus formation but not affecting plaque
biofilm
Answer: A. It disrupts bacterial cell membranes and precipitates cytoplasmic
contents, exhibiting substantivity due to binding to oral tissues
Rationale: Chlorhexidine is a bisbiguanide that disrupts microbial cell membranes and
precipitates cell contents; its cationic nature allows binding to oral tissues, providing
prolonged substantivity. It is not an anti-inflammatory agent, not a quaternary ammonium
compound, and does not primarily chelate calcium.
6. During administration of an inferior alveolar nerve block, the patient reports a
sudden sharp pain and the clinician notes the syringe plunger is difficult to depress.
Which complication is most likely occurring?
A. Intravascular injection into the inferior alveolar artery
B. Needle contact with the mandibular nerve causing paresthesia
C. Needle deflection into the parotid gland
D. Trismus due to medial pterygoid muscle trauma
Answer: B. Needle contact with the mandibular nerve causing paresthesia
Rationale: A sudden sharp pain during injection often indicates needle contact with the
nerve, which can lead to paresthesia. Intravascular injection would present with rapid
onset of systemic symptoms, not difficulty depressing the plunger. Parotid gland
involvement and trismus typically occur from different mechanisms and are not
characterized by sharp pain during injection.
Page 4 of 80
