Coming soon · ACJ · NDEB (Canada)
Assessment of Clinical Judgement.
Step two of the Canadian NDEB Equivalency Process — case-based clinical reasoning, diagnosis, treatment planning, and radiographic interpretation. ~150 single + multi-answer items in 5 hours.
ACJ prep isn’t live on Lumen yet. Drop your email and we’ll let you know the moment our diagnostic + mocks open.
Blueprint · topic weights
6 domains, honestly weighted.
Once ACJ prep is live, our diagnostic + mocks will sample in proportion to the published NDEB (Canada) competency document — never random.
01Oral Medicine/Oral Pathology, Oral SurgerySoft-tissue lesions, oral pathology, exodontia, surgical complications, biopsy decisions. Official weight: 25 ± 5%.25%
02Pharmacotherapeutics, Medically-Complex Patients, Medical Emergencies, Geriatrics, Local AnesthesiaDrug interactions, dental pharmacology, medically-complex patient management, in-office medical emergencies, geriatric care considerations, local anesthetic dosing and complications. Official weight: 22 ± 5%.22%
03Cariology/Restorative DentistryCariology, restorative materials and techniques, indirect restorations, occlusion. Official weight: 18 ± 5%.18%
04PeriodonticsPeriodontal classification (2017 AAP/EFP), non-surgical and surgical therapy, peri-implant disease, maintenance. Official weight: 15 ± 5%.15%
05EndodonticsPulpal/periapical diagnosis, canal anatomy, instrumentation, obturation, retreatment decisions. Official weight: 10 ± 5%.10%
06Orthodontics, Pediatric DentistryMalocclusion analysis, growth and development, behaviour management, primary-dentition trauma, paediatric pharmacology. Official weight: 10 ± 5%.10%
FAQ
Everything candidates ask about ACJ.
- Who writes the NDEB ACJ?
- The Assessment of Clinical Judgement (ACJ) is the second NDEB Equivalency Process exam for internationally trained dentists pursuing Canadian licensure. Candidates must first pass the AFK before they can sit the ACJ.
- What is the ACJ exam format?
- The ACJ is a computer-based exam of approximately 150 (120–150) single- and multiple-answer clinical reasoning items spanning diagnosis, treatment planning, clinical decision-making, and radiographic interpretation. It runs five hours with one scheduled break. Cases are built around short stems with described radiographic and clinical findings, dental charts, and intraoral photographs.
- What is the ACJ pass mark?
- The NDEB uses test equating and re-scaling against a reference examination, so the pass mark is a fixed test-equated, re-scaled score of 75. Results are reported as Pass/Fail; candidates scoring below 75 also receive their test-equated re-scaled score. (Separately, first-time pass rates for AFK-passers run in the 70–80% range — that is a pass rate, not the pass mark.)
- How long should I study for the ACJ?
- Most candidates allocate 8 to 12 weeks after AFK, focused on clinical reasoning over recall. Time spent on radiograph interpretation, pulpal and periapical diagnosis, and treatment sequencing pays back disproportionately on test day.
- How many ACJ attempts are allowed?
- The NDEB allows up to three ACJ attempts. After three failures, additional remediation or restart of the Equivalency Process may be required.
- What does Lumen's ACJ module cover?
- Lumen's ACJ module is case-pack focused — diagnosis, treatment planning, complications — with rationales tied to current Canadian competency guidelines and the diagnostic surfaces your weakest clinical-reasoning sub-areas first.
- 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.
In the meantime
Try a live exam while you wait.
Other dental board exams are already live — same weighted blueprints, same clinician-signed rationales.