Frontispiece · NBDHE study atlas
The hygienist's atlas.
Hygiene Atlas is a free, image-first reference and study guide for dental hygiene students and working RDHs. It maps all 19 topic areas of the National Board Dental Hygiene Examination into 155 illustrated sub-topics, written in plain language from cited sources.
The exam at a glance
What the NBDHE actually asks
The National Board Dental Hygiene Examination is written by the Joint Commission on National Dental Examinations (JCNDE) and given at Pearson VUE centers. Every US state uses it as the written part of licensure.
Source: JCNDE NBDHE Candidate Guide, 2026.
- 350
- multiple-choice items
- 200
- discipline-based items in session 1 (3 h 30 min)
- 150
- case-based items on 12–15 patient cases
- 9 h
- total seat time, 7 h 30 min of testing
- 75
- minimum passing scale score (range 49–99)
- 1–32
- Universal tooth numbering on every item
Contents · 19 plates
Every board topic, one plate each
Topics are grouped the way the JCNDE test specifications group them. Item counts show the current specifications and, after the arrow, the update expected in November 2026.
Scientific Basis for Dental Hygiene Practice
61 → 56 items
- I Head and Neck Anatomy 9 topics
- II Dental Anatomy and Tooth Morphology 10 topics
- III Histology and Embryology 7 topics
- IV Physiology 7 topics
- V Biochemistry and Nutrition 6 topics
- VI Microbiology and Immunology 8 topics
- VII General and Oral Pathology 9 topics
- VIII Pharmacology and Local Anesthesia 12 topics
Provision of Clinical Dental Hygiene Services
115 → 124 items
- IX Dental Radiography 11 topics
- X Periodontology 8 topics
- XI Instrumentation 10 topics
- XII Patient Assessment and Charting 6 topics
- XIII Medical Emergencies 9 topics
- XIV Infection Control 10 topics
- XV Caries and Preventive Agents 9 topics
- XVI Supportive Treatment Services 4 topics
- XVII Patient Management and Special Needs 8 topics
- XVIII Ethics and Professional Responsibility 6 topics
Community Health and Research Principles
24 → 20 items
Questions
Frequently asked
Is Hygiene Atlas free?
Yes. Every page is free to read with no account and no paywall. Study progress is kept in your own browser.
Who is it for?
Dental hygiene students preparing for the National Board Dental Hygiene Examination (NBDHE), and working hygienists who want a quick visual refresher on anatomy, instruments, radiographs, pathology and clinical protocols.
What does the NBDHE cover?
The NBDHE has 350 multiple-choice items: 200 discipline-based items in three areas (scientific basis, clinical services, and community health and research) plus 150 case-based items built on 12 to 15 patient cases. A scale score of 75 passes.
Which version of the test specifications does it follow?
Both. JCNDE is moving from the current specifications (61 scientific, 115 clinical, 24 community items) to updated ones expected in November 2026 (56, 124 and 20). Each topic shows where it sits in both versions.
Is this an official JCNDE or ADA product?
No. Hygiene Atlas is an independent study aid. It does not reproduce any JCNDE exam or sample items; every question is written from scratch.
Where do the images come from?
Hero and diagram art is rendered in Blender for this site. Photos and engravings are public domain or Creative Commons, credited under each image and listed on the sources page.
Is the content up to date?
It reflects current guidance as of October 2026, including the 2017 AAP/EFP periodontitis staging and grading, the AHA 2021 endocarditis prophylaxis update, and the ADA 2024 radiation-shielding recommendations.