Question 1
A 54-year-old woman with rheumatoid arthritis reports a dry mouth and gritty, dry eyes for the past 2 years. Her parotid glands are enlarged on both sides, and she has new cervical caries. Which condition is most likely?
Dental hygiene board exam prep
How hard is the NBDHE?
Most first-time candidates from accredited programs pass, but not all: 10.1% failed in 2025, and more than half of retakes failed (54.9%). The difficulty is breadth and stamina: 350 questions across the whole curriculum in 7 hours 30 minutes of testing.
| First attempts failed, 2025 | 10.1% of 7,893 accredited candidates |
|---|---|
| Retakes failed, 2025 | 54.9% of 1,560 |
| Testing time | 7 hours 30 minutes in two sessions |
| Pace | About 63 seconds a question in Session One, about 96 in Session Two |
What makes it hard
- Breadth: anatomy, pathology, pharmacology, radiography, periodontics, materials, ethics and research all appear on one exam.
- Cases: 150 questions turn on reading a patient box well, catching the medication, vital sign or history entry that changes care.
- Stamina: two sessions of 3 hours 30 minutes and 4 hours in one day.
- Current standards: the questions follow the 2017 periodontal classification, the 2021 AHA prophylaxis statement and the 2020 ASA classification, among other updates the JCNDE lists.
Where to start
Take a short diagnostic across every area first and spend most of your time on the weakest. Practise patient cases as whole cases, reading the box before the questions, and sit at least one full session on the clock before test day.
Try 2 questions
Question 2
A 34-year-old patient with type 1 diabetes took her insulin but skipped breakfast. Midway through scaling she becomes shaky, sweaty and confused, but she can swallow and follow commands. What should the hygienist give her?
Next step
Questions people ask
Is the NBDHE hard to pass?
Most first-time candidates from accredited programs pass: 89.9% did in 2025. Retakes are harder: 45.1% passed.
What is the hardest part of the NBDHE?
The exam itself does not name one. Its demands are breadth, with every part of the curriculum on one exam, and the case session, where each case needs careful reading of the patient box before its questions.
How long should I study for the NBDHE?
The JCNDE does not say. Base it on a diagnostic: the weaker your scores across areas, the longer you need.