ADAT · ADA (United States)
Advanced Dental
Admission Test.
Free 20-question ADAT diagnostic, built from real exam-style items. See exactly where you stand across all 3 domains in about 30 minutes — no signup to start, instant topic-gap report.
20 questions · ~30 min · no signup to start · instant topic-gap report
Mock variants
4 ways to sit ADAT.
Blueprint · topic weights
3 domains, honestly weighted.
Diagnostic and mock items are sampled in proportion to the published ADA (United States) competency document — never random.
01Biomedical Sciences80 items across four 20-item sub-areas per the 2026 ADAT Candidate Guide: Anatomic Sciences (gross anatomy, histology, oral histology, developmental biology); Biochemistry and Physiology (biological compounds, metabolism, molecular and cellular biology, nervous system, circulation, respiration, renal, oral physiology, digestion, endocrines); Microbiology and Pathology (general microbiology, reactions of tissue to injury, immunology and immunopathology, systemic pathology, growth disturbances); Dental Anatomy and Occlusion (tooth morphology, pulp cavity morphology, calcification and eruption, principles of occlusion and function).40%
02Clinical Sciences80 stand-alone and case-based items across ten verbatim sub-areas per the 2026 ADAT Candidate Guide: Endodontics; Operative Dentistry; Oral and Maxillofacial Surgery and Pain Control; Oral Diagnosis; Orthodontics and Pediatric Dentistry; Periodontics; Pharmacology; Prosthodontics; Principles of Ethics; Patient Management.40%
03Data, Research Interpretation, and Evidence-Based Dentistry40 items across four verbatim sub-areas per the 2026 ADAT Candidate Guide: Study Design, Data Analysis, Result Interpretation, Inference and Implication. Section focuses on critically reviewing research findings, understanding methodological issues (clinical trial design, descriptive statistics, odds ratios, risk reduction, relative risk), and applying evidence-based clinical guidelines and systematic reviews.20%
FAQ
Everything candidates ask about ADAT.
- Who should take the ADAT?
- The Advanced Dental Admission Test (ADAT) is administered by the ADA Council on Dental Education and Licensure (CDEL) and used by advanced dental education programs (ortho, perio, endo, OMFS, prosth, peds, AEGD, GPR, etc.) to compare applicants on a common scale alongside transcripts, letters, and interviews. Eligible candidates are dental students or graduates from CODA or CDAC-accredited schools, plus graduates of non-accredited schools with an ECE evaluation report.
- What is the ADAT exam format?
- The 2026 ADAT is a computer-based exam of 200 multiple-choice items across three sections: Biomedical Sciences (80 items, 95 minutes); Clinical Sciences (80 stand-alone and case-based items, 90 minutes); Data, Research Interpretation, and Evidence-Based Dentistry (40 items, 45 minutes). Total testing time is 230 minutes; total session including 15-minute tutorial and two 10-minute optional breaks is 4 hours 30 minutes.
- How is the ADAT scored?
- ADAT results are reported as scaled scores ranging from 200 to 800 in 10-point increments. There is NO official passing score — each advanced dental education program sets its own acceptable threshold. Scores are not raw counts or percentiles; they are equated psychometrically so candidates on different test forms compare fairly. Candidates are not penalized for guessing. Some items are experimental and unscored (indistinguishable from scored items during the exam).
- When is the ADAT administered?
- The 2026 ADAT testing window runs March 1 through August 31, 2026. Candidates schedule a single appointment at a Pearson Professional Center within that window. Most applicants sit ADAT in late spring or summer to leave room for a retake before residency application deadlines if needed.
- Can I retake the ADAT?
- Yes. Candidates must wait at least 45 days between testing attempts and are limited to 2 attempts per testing window. Candidates who have taken the ADAT two or more times previously are limited to 1 attempt per window and must submit evidence of having actively applied to advanced dental education programs within the previous 18 months. All retake history is reported to programs.
- How much does the ADAT cost?
- The 2026 ADAT examination fee is USD $465 (includes administration plus score reports to programs selected at time of application). Candidates from non-CODA dental schools pay an additional $435 processing fee. Optional fees: $55 per additional score report, $105 for a score audit, $25 for rescheduling. Partial 50% fee waivers are available January 1 each year for first-time candidates demonstrating financial hardship.
- How does Lumen's ADAT prep work?
- Lumen's ADAT module ships items modeled on the 2026 ADAT Candidate Guide content outline: Biomedical (Anatomic Sciences, Biochem and Physiology, Microbiology and Pathology, Dental Anatomy and Occlusion); Clinical (Endo, Operative, OMFS, Oral Diagnosis, Ortho and Pedo, Perio, Pharmacology, Prosth, Principles of Ethics, Patient Management); Data/Research/EBD (Study Design, Data Analysis, Result Interpretation, Inference and Implication). The diagnostic surfaces your weakest sub-areas so study time goes where it moves the score.
- How do I sign up for Lumen?
- You can take the free diagnostic without an account. To save attempts, see rationales, and unlock full mocks, sign in with email — we send a magic link, no password to forget.
- Are rationales reviewed by clinicians?
- Yes. Every item ships with a clinician-written rationale that cites the published competency guideline it maps to. Items flagged by users get re-reviewed within a business day.
From the blog
Further reading.
Why Lumen for ADAT
Built by clinicians, priced for students.
01
Blueprint-aligned items.
Topic weights match the published competency document. No guessing what the test cares about.
02
Every rationale signed.
A licensed clinician wrote, reviewed, and cited every explanation. Flag one and we re-review within a day.
03
Diagnostic before you pay.
Free 20-item diagnostic with full topic gap analysis. No credit card. Decide if we’re right for you, then upgrade.
Independent study tool. Not endorsed by NDEB, ADA, or JCNDE. We do not promise passing scores. All items are exam-style and based on publicly available competency guidelines.