Dental Hygiene Board Exams: The NBDHE and Your Clinical Exam

The dental hygiene board exam is really two exams: the National Board Dental Hygiene Examination (NBDHE), a 350-question written test, and a hands-on clinical exam. Most states require both before they license you, and many add requirements of their own.

As of 2026, the NBDHE costs $600, takes 7 hours 30 minutes of testing, and is scored pass/fail, according to the JCNDE's 2026 NBDHE Candidate Guide (opens in a new tab). Below: how each exam works, how scoring works, a 12-week study plan, and what to do if you don't pass.

The two exams you need before a license

The NBDHE tests what you know. The clinical exam tests what you can do with your hands. They're run by different organizations, and you register for each one separately.

Passing both exams doesn't license you by itself. You still apply to your state board, and most states also require a jurisprudence exam, CPR/BLS, and a background check. The guide to getting your dental hygiene license walks through that part.

NBDHE at a glance

JCNDE plans new NBDHE test specifications for November 2026 (opens in a new tab) (its candidate guide says October). If you test after the change, study the "after the update" column below, and check JCNDE's NBDHE page for the current date before you build your plan.

What the questions cover

The discipline-based questions fall into three areas. The update shifts a few questions from the science and community health areas into clinical services, and renames the third area "Research Principles and Community Health":

Case-based questions give you a patient history, dental chart, radiographs, and clinical photos, then ask about assessment, radiographs, care planning, periodontal treatment, preventive agents, supportive services, and professional responsibility. Cases can include children, older adults, periodontal patients, people with special needs, and medically compromised patients. The exam uses the Universal/National tooth numbering system (1 to 32 for permanent teeth, A to T for primary teeth).

How NBDHE scoring works

Your official result is simply pass or fail. Behind it is a scale score from 49 to 99, and 75 is the minimum passing score. A 75 is not 75% correct, and it isn't the number of questions you got right. JCNDE converts your raw score to the scale so that a 75 means the same thing on every version of the exam, even if one version is slightly harder.

• Only the overall score counts. You don't have to pass each area separately, so a weak subject won't sink you if the rest is strong.
• If you pass, your report says pass. You don't get a number.
• If you fail, you get your overall scale score plus performance information for 13 discipline areas and the case area. That breakdown is your retake study plan.

NBDHE pass rates

JCNDE publishes failure rates in its 2025 NBDHE Technical Report (opens in a new tab) (Table 15.2). In 2025, 10.1% of first-time candidates from CODA-accredited programs failed (7,893 candidates), so about 90% passed on their first try. Retakes are harder: 54.9% of accredited-program candidates who were retaking the exam failed. First-time failure rates for accredited-program candidates have ranged from 5.1% to 14.3% over 2016 to 2025.

Your own program's record matters more than the national number. When you apply, you give JCNDE permission to share your results with your program, so programs know how their graduates do. Ask your program (or any program you're considering) for its first-time NBDHE pass rate for the last few years, and treat the retake numbers as a reason to prepare well the first time.

The clinical board exam (ADEX and CRDTS)

The clinical exam checks that you can perform dental hygiene care safely and to standard while examiners grade your work. Depending on the exam and the state, you work on a live patient or a manikin.

Two mergers left two main clinical exams: ADEX and CRDTS. A few states also accept or give other exams. In August 2025, CDCA-WREB-CITA and ADEX finalized their merger (opens in a new tab) as the American Board of Dental Examiners (ADEX). The former WREB and CITA exams are now given as the ADEX exam. ADEX says it serves 85% of dental hygiene licensure candidates and that its exam is required or recognized by law for licensure in nearly every U.S. jurisdiction. In January 2025, SRTA merged into CRDTS (opens in a new tab), which still offers its own dental hygiene exam.

Older board rules may still name WREB, CITA, or SRTA. Those exams now run as ADEX or CRDTS. Not every state accepts both, so confirm your state before you register. See dental hygiene license requirements by state for the exams each state accepts.

• Pick the exam for where you'll work, not where it's most convenient to test. If you might move, choose an exam both states accept.
• Read the exam's candidate guide early. It sets the patient criteria, instruments, and timing rules.
• If your exam uses a live patient, start looking early. Finding a patient who meets the criteria is a common bottleneck. Line up a backup, too.
• Ask your program what past classes did. Faculty know which exam most graduates take and how to prepare for it.

How long to study: a 12-week NBDHE plan

Plan on about 12 weeks of steady review alongside your final term. If you have less time, start at the "8 to 5 weeks out" row and spend less time on your strongest areas. Four weeks is a sprint, and it works best if your coursework is already solid.

If you're still in classes, the habits in how to survive dental hygiene school (active recall and spaced review) are the same ones that carry you through boards.

How to study for the NBDHE

• Start with official material. JCNDE offers free NBDHE sample questions and sells practice test modules through Pearson VUE (details are in the candidate guide (opens in a new tab)). JCNDE notes that practice results don't predict your real score, so use them to learn the format and find weak spots.
• Quiz yourself instead of rereading. Answering questions from memory builds recall. Rereading notes feels productive but mostly builds familiarity.
• Keep an error log. For every miss, write why you missed it: didn't know it, misread it, or changed a right answer. Patterns tell you what to fix.
• Practice cases on their own. For case-based items, read the question first, then go back to the history, chart, and radiographs for the facts you need. Check the medical history before any treatment question.
• Pace yourself. Session one gives you 3 hours 30 minutes for 200 questions. Session two gives you 4 hours for 150. Each session has an optional 15-minute break that doesn't count against your question time, so take it.
• Answer every question. Your raw score counts correct answers, so a blank earns nothing.
• Study the specs for your test date. If you test after the November 2026 update, weight clinical services a little more.

If you don't pass the NBDHE

Failing the NBDHE is a setback, not the end. You can apply again, within limits:

• Wait at least 60 days between attempts.
• Take no more than 4 attempts in any 12 months. If you use all 4, you can't take a fifth until 12 months after the first of them.
• Pass within 5 years of your first attempt or within 5 attempts, whichever comes first. After that, JCNDE allows one attempt every 6 months.
• Each retake is a new application, and fees are nonrefundable.

Use the 60 days. Start from your performance report: study the lowest areas first, then take a full timed practice run before you rebook. Clinical exam retake rules are set by each testing agency, so check its candidate guide if you need to retake that exam.

Once both exams are behind you, the next step is your state application. The license guide covers what state boards ask for and how moving states works.

Frequently asked questions