NBDHE Cheat Sheet 2026

The 30 highest-yield NBDHE facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What class of dental product includes Listerine and Scope? → Mouthwash
2. A periapical radiograph showing a well-defined radiolucency with a sclerotic border at the apex of a vital tooth is MOST likely: → Periapical cemento-osseous dysplasia (early stage)
3. Secondary prevention in dentistry is best illustrated by: → Early detection and treatment of incipient gingivitis
4. A patient with chronic obstructive pulmonary disease (COPD) requires dental hygiene treatment. Which modification is most important? → Positioning the patient semi-upright and minimizing use of water spray near the airway
5. The Bass toothbrushing technique is most effective at removing plaque from: → The gingival sulcus and margin
6. What is the PURPOSE of an external chemical indicator (Type 1 process indicator) placed on a sterilization package? → Confirms that the package was exposed to the sterilization process
7. In Glickman's classification of furcation involvement, a Class II furcation is best described as a defect in which: → The probe enters the furcation but does not pass through to the opposite side
8. Erythroplakia is clinically significant because it has a higher malignant transformation rate than which lesion? → Leukoplakia
9. Which oral lesion appears as a white, non-removable plaque on the oral mucosa that cannot be attributed to any other known disease? → Leukoplakia
10. Which item is classified as 'semicritical' in the Spaulding classification system? → Reusable impression tray
11. During active periodontal debridement with a hand curette, the correct working angulation of the blade face against the tooth surface is: → 45 to 90 degrees
12. Kaposi's sarcoma in the oral cavity appears most frequently on which structure? → Hard palate and gingiva
13. A patient asks how long they should brush their teeth. The evidence-based recommendation for toothbrushing time is: → 2 minutes
14. Who served as the first president of the American Dental Hygienists' Association upon its founding? → Gillette Hayden
15. Which of the following systemic conditions is most associated with hypercementosis and hypoplastic enamel in primary teeth? → Vitamin D-resistant rickets (X-linked hypophosphatemia)
16. What does the acronym 'ADHA Standards of Clinical Dental Hygiene Practice' include as the five components of the dental hygiene process? → Assessment, Dental Hygiene Diagnosis, Planning, Implementation, and Evaluation
17. The Oral Hygiene Index-Simplified (OHI-S), developed by Greene and Vermillion, is calculated by combining scores from which two sub-indices? → Debris Index and Calculus Index
18. Fluoride can be found in what sources? → Water
19. OSHA's Bloodborne Pathogens Standard requires employers to offer hepatitis B vaccination to: → Employees with potential occupational exposure to blood or OPIM
20. Which U.S. state was the first to legally license dental hygienists, doing so in 1917? → Connecticut
21. The primary purpose of the lead apron with thyroid collar in dental radiography is to: → Protect radiosensitive tissues — gonads and thyroid — from scatter radiation
22. When calculating the sensitivity of a diagnostic test for periodontitis, which value represents the percentage of people WITH the disease who test positive? → True positive / (True positive + False negative) × 100
23. When treating an elderly patient with dementia, which legal and ethical principle is most important before beginning treatment? → Verifying that informed consent is obtained from the legal guardian or healthcare proxy
24. Which systemic condition is associated with gingival fibromatosis and multiple odontomas? → Gardner syndrome
25. When treating a patient with cerebral palsy, which positioning modification is most important during dental treatment? → Keeping the patient in a semi-upright position to reduce involuntary movements
26. The Snyder test measures which property of saliva? → Cariogenic potential via acid production from glucose
27. Which instrument is used to condense amalgam into a prepared cavity? → Amalgam condenser (plugger)
28. The Silness and Löe plaque index scores plaque based on: → Thickness of plaque at the gingival margin
29. Which element is NOT required to establish dental malpractice? → Proof that the patient disliked the treatment outcome
30. Professionally applied fluoride varnish provides caries protection primarily through: → A sustained topical fluoride reservoir on tooth surfaces