How Many Questions Are on the Dental Hygiene National Board?

I. Overview of the NBDHE

The National Board Dental Hygiene Examination (NBDHE) is a required written examination for candidates who seek to obtain their licensure and to practice as a licensed dental hygienist.

II. Structure and Format of the Exam

The National Board Dental Hygiene Examination is administered over the course of 9 hours, including the optional tutorial, an optional 30 minute scheduled break, and post-examination survey. There are two sections of the exam that are separated by an optional break: the first section consists of discipline based items, such as fundamental sciences, and the second section consists of dental hygiene patient cases, which often assesses the candidates knowledge of clinical dental hygiene services. The format of the exam are multiple choice questions.

III. Number of Questions on the NBDHE

There are 350 questions throughout the entire exam. The first session will consist of 200 multiple choice questions that are discipline based while the second session will have 150 multiple choice questions that are case-based.

IV. How Many Questions Can You Miss on the NBDHE?

The NBDHE uses a scaled scoring system ranging from 49 to 99, with 75 as the minimum passing score. Because these scores are not a raw score and does not adequately reflect the exact number of questions answered correctly, there is no fixed margin of error for how many questions a candidate can answer incorrectly and still pass. For example, a raw score of 74 does not necessarily mean that an additional correctly answered question would result in a passing score.

V. Scoring and Passing the NBDHE

Results are equated across multiple administered versions of the exam to adjust for differences in difficulty, meaning a scaled score of 75 always represents the same level of competency regardless of the specific test form. This scaling process ensures fairness and consistency in determining whether a candidate meets the passing standard.

If you weren't successful in passing, don't panic! Candidates are able to apply for re-examination after a minimum of 60 days after their most recent unsuccessful attempt. Be aware that there is a five year/five attempts rule where candidates must pass within five years of their first attempt or within their first five attempts. After that, candidates are eligible to attempt the exam every 12 months.

VI. Distribution of Questions Across Sections

The NBDHE exam evaluates candidates with discipline based questions and case-based questions.

The discipline based items, with 200 questions, will address three components: scientific basis for dental hygiene practice, provision of dental hygiene services, and community health and research principles.

The case-based items will consist of about 12 to 15 dental hygiene patient cases that cover functions that a dental hygienist is expected to perform and will be supplemented with patient characteristics, charts, and diagnostic images. This section typically consists of 150 case relevant questions.

VII. Time Management Tips

The exam itself runs for a total of 7 hours 30 minutes of testing time within a 9-hour administration window. Session One is 3 hours 30 minutes long for 200 discipline-based questions and Session Two provides 4 hours for 7–8 patient cases (about 150 questions). Candidates are allowed an optional 15-minute break within each session and a 30-minute break between sessions, but the timer does not stop outside of these scheduled breaks.

Pro-Tip: It’s important to pace yourself by monitoring the clock to avoid rushing. Try using scheduled breaks to reset and avoid spending too long on difficult questions during the exam. There is no penalty for guessing, so it’s important to answer all questions and return to challenging ones before the time limit.

VIII. Strategies for Success on the NBDHE

To be successful in achieving a passing NBDHE score, it is essential to use practice tests and question banks to strengthen your scientific basis, community health research principles, provision of clinical dental knowledge, and to practice your approach to dental hygiene patient cases.

Pro-Tip: Start preparing early! If you find that test day is approaching soon and you need a structured study schedule, BoosterPrep provides a recommended 8-week study schedule found here.

Pro-Tip: Try out BoosterPrep's NBDHE tutor found here for additional guidance or if there are specific skills or areas related to dental hygiene that you would like to focus on.

IX. Common Mistakes to Avoid

The two sessions of the exam are enforced with strict time limits. Try to simulate the testing environment to ensure that you are able to manage your time so that you are well prepared for test day.

Additionally, avoid the habit of overthinking questions. Using practice questions, develop a technique to quickly assess the difficulty of a question. Because there are no penalties for guessing, it is important to answer all of the multiple choice questions.

As you prepare for the NBDHE exam, identify the weak content areas and ensure you focus on these subjects. Avoid ignoring subjects that you are weak or unfamiliar with as this will only create challenges for you as you prepare for the exam and on test day.

X. Resources for NBDHE Preparation

As you are preparing for the NBDHE exam, ensure that you are familiar with the official testing guidelines. This article provides a good summary but further information on the scaled scoring system and administration scheduling can be found here.

We also recommend taking frequent practice tests to identify weak subject areas to review and to simulate test day. Build your skills in time management so that you can take the exam with confidence.

Pro-Tip: Need preparation resources? Check out BoosterPrep's tools that covers areas such as clinical dental hygiene services, pharmacology, pathology and oral diseases, community health, periodontal procedures including dental hygiene care, and other key subjects that cover the functions of dental hygiene practice.

XI. FAQ

Q: How long is the NBDHE exam?

A: The exam will be administered over a 9 hour window, this includes optional breaks during and between sessions. The actual writing of the exam is 7 hours and 30 minutes split into two sessions with session one covering 3 hours and 30 minutes and session two covering 4 hours.

Q: What is the passing score?

A: The passing score on a scaled scoring system is 75. The NBDHE uses a scaling process by obtaining raw scores across multiple versions of the exams to ensure fairness and to adjust for difficulty among different versions of the exam.

Q: How much does the NDBHE cost?

A: As of October 8, 2025 the NDBHE examination fees are $600 US dollars.

Congratulations on your journey towards becoming a licensed dental hygienist! For further questions or resources for dental hygiene related subjects, BoosterPrep is here to provide additional tools to guide you towards success.