ADEX crown prep
ADEX vs Other Clinical Dental Exams: ADEX and CRDTS Compared
Last updated · Facts checked against the ADEX candidate manual for August 1, 2026 – July 31, 2027 and each agency's site (2026-10-03)
Our summary of the agencies' own pages: The American Board of Dental Examiners, formed when CDCA-WREB-CITA and ADEX merged in August 2025, runs the ADEX exam, and Central Regional Dental Testing Service (CRDTS) runs its own. SRTA has merged with CRDTS. Both agencies' hands-on exams use manikins; each state board decides which exams it accepts.
Sources for this summary: ADEX: CDCA-WREB-CITA and ADEX merger announcement (opens in a new tab); CRDTS: SRTA merger page (opens in a new tab); ADEX Dental Candidate Manual, Clinical (PDF) (opens in a new tab); CRDTS Dental examination page (opens in a new tab).
| Detail | ADEX (American Board of Dental Examiners) | CRDTS |
|---|---|---|
| Who runs it | The American Board of Dental Examiners, formed when CDCA-WREB-CITA and ADEX merged in August 2025.Source: ADEX: CDCA-WREB-CITA and ADEX merger announcement (opens in a new tab) | Central Regional Dental Testing Service (CRDTS).Source: CRDTS home page and portability map (opens in a new tab) |
| Exam parts | The ADEX Dental Examination combines the computer-based DLOSCE with five clinical exams: Periodontal, Endodontic, Prosthodontic, Anterior Restorative and Posterior Restorative. All parts must be passed within 18 months of the first attempt of any part.Source: ADEX Dental Examination page (opens in a new tab) (Examination Fees: the five clinical exams and the DLOSCE); ADEX Candidate Guide (PDF) (opens in a new tab) (The ADEX Examination Series & 18-Month Rule: the 18-month rule) | Five parts: Part I, the Diagnosis and Comprehensive Treatment Planning (DCTP) written examination; Part II, Endodontic; Part III, Prosthodontic; Part IV, Periodontal, with an OSCE; Part V, Restorative.Source: CRDTS Dental examination page (opens in a new tab); CRDTS Dental Examination Overview, Policy and Procedures (PDF) (opens in a new tab) (Content Overview) |
| Manikin or patient | The clinical exams are performed on simulated patient manikins and proprietary typodont models, in a clinic or simulation laboratory.Source: ADEX Dental Candidate Manual, Clinical (PDF) (opens in a new tab) (Examination Overview) | Simulated exams are completed on a manikin.Source: CRDTS Dental examination page (opens in a new tab) |
| Prosthodontic exam | Up to four hours for three crown preparations: an all-ceramic crown on a central incisor, and zirconia crowns on a premolar and a molar as the abutments of a 3-unit bridge.Source: ADEX Dental Candidate Manual, Clinical (PDF) (opens in a new tab) (Examination Overview; Endodontic & Prosthodontic Performance Expectations) | 4.0 hours for four procedures on artificial teeth: a porcelain-fused-to-zirconia crown preparation on tooth #5 and a monolithic zirconia ceramic crown preparation on tooth #3 as the abutments of a 3-unit bridge, a bridge factor scoring their line of draw, and a lithium disilicate ceramic crown preparation on tooth #9.Source: CRDTS Dental Examination Overview, Policy and Procedures (PDF) (opens in a new tab) (Content Overview: Part III, Fixed Prosthodontics Examination) |
| Scoring and results | Examiners rate each criterion Clinically Acceptable, Marginally Substandard or Critically Deficient. A score of 75 or greater is required to pass each part, and results are reported as pass or fail.Source: ADEX Dental Candidate Manual, Clinical (PDF) (opens in a new tab) (Scoring Overview — Endodontic and Prosthodontic Exams) | Three examiners rate each criterion independently; for the majority of criteria, the four rating levels are Satisfactory, Minimally Acceptable, Marginally Substandard and Critically Deficient. A score of 75 or more is required on each procedure within each part, and a score is reported for each procedure.Source: CRDTS Dental Examination Overview, Policy and Procedures (PDF) (opens in a new tab) (Scoring System; Re-examination: Retests) |
| Retakes | Failing one crown preparation means retaking the whole Prosthodontic exam. A 10-day waiting period applies before any retake, and three failed attempts of the same part fail the entire exam series.Source: ADEX Candidate Guide (PDF) (opens in a new tab) (10-Day Retake Waiting Period; ADEX 3-Time Fail Policy); ADEX Dental Candidate Manual, Clinical (PDF) (opens in a new tab) | Only failed procedures are retaken, with a second attempt available on-site at most exam sites. A 30-day wait applies before a third attempt, and failing the third attempt means retaking every procedure in that part. A score below 75 on the Prosthodontic Bridge Factor negates the previous scores for teeth #3 and #5, and the retake covers both abutment preparations and the Bridge Factor.Source: CRDTS Dental Examination Overview, Policy and Procedures (PDF) (opens in a new tab) (CRDTS Retake Policy; Retests Parts I, II, III, IV & V) |
| Exam fee | $2,995 for the full ADEX Dental series, plus a facility fee that varies by location and a $150 typodont fee per procedure. It includes one complimentary retake per clinical procedure.Source: ADEX Dental Examination page (opens in a new tab) (Examination Fees – ADEX Dental Series) | $2,800 for Parts I to V, not including site or rental fees. One complimentary retake for a single failed procedure; additional procedure retakes are $225 each, up to $700 per part.Source: CRDTS Dental examination page (opens in a new tab) (Class of 2027 Dental Fees) |
| Where it is accepted | ADEX publishes an acceptance map for initial licensure. Jurisdictions not accepting the ADEX Dental Examination include Delaware and New York (map last updated 3/6/2026). Prior to registering for any exam, candidates should check with the appropriate state board to verify current licensing requirements.Source: ADEX acceptance map (opens in a new tab) (map notes and disclaimer) | CRDTS publishes a portability map and says its exams are recognized and accepted in over 40 states. Candidates must confirm acceptance, and whether a simulated patient exam is acceptable, with each state.Source: CRDTS home page and portability map (opens in a new tab) |
Sources: each agency's own website and candidate manuals, 2026–2027 season. Confirm current details with the agency and your state board.
Which agencies run clinical dental licensure exams in 2026?
ADEX: The American Board of Dental Examiners, formed when CDCA-WREB-CITA and ADEX merged in August 2025.
CRDTS: Central Regional Dental Testing Service (CRDTS). SRTA has merged with CRDTS.
Each state dental board sets its own clinical requirements. Many states accept several pathways, such as a PGY-1 residency, the DLOSCE (JCNDE), the NDEB OSCE or the 2014 California Portfolio Exam. Delaware administers its own patient exam and New York requires a PGY-1 residency.
Are the ADEX and CRDTS exams done on manikins or patients?
ADEX: The clinical exams are performed on simulated patient manikins and proprietary typodont models, in a clinic or simulation laboratory.
CRDTS: Simulated exams are completed on a manikin.
How do the ADEX and CRDTS crown preps compare?
ADEX: Up to four hours for three crown preparations: an all-ceramic crown on a central incisor, and zirconia crowns on a premolar and a molar as the abutments of a 3-unit bridge.
CRDTS: 4.0 hours for four procedures on artificial teeth: a porcelain-fused-to-zirconia crown preparation on tooth #5 and a monolithic zirconia ceramic crown preparation on tooth #3 as the abutments of a 3-unit bridge, a bridge factor scoring their line of draw, and a lithium disilicate ceramic crown preparation on tooth #9.
Our crown prep guide covers only the ADEX Prosthodontic exam, not the CRDTS exam.
How are the ADEX and CRDTS exams scored?
ADEX: Examiners rate each criterion Clinically Acceptable, Marginally Substandard or Critically Deficient. A score of 75 or greater is required to pass each part, and results are reported as pass or fail.
CRDTS: Three examiners rate each criterion independently; for the majority of criteria, the four rating levels are Satisfactory, Minimally Acceptable, Marginally Substandard and Critically Deficient. A score of 75 or more is required on each procedure within each part, and a score is reported for each procedure.
Which states accept the ADEX or CRDTS exam?
ADEX: ADEX publishes an acceptance map for initial licensure. Jurisdictions not accepting the ADEX Dental Examination include Delaware and New York (map last updated 3/6/2026). Prior to registering for any exam, candidates should check with the appropriate state board to verify current licensing requirements.
CRDTS: CRDTS publishes a portability map and says its exams are recognized and accepted in over 40 states. Candidates must confirm acceptance, and whether a simulated patient exam is acceptable, with each state.
Only state boards of dentistry are legally authorized to set the standards for licensure, and completing the CRDTS exam alone does not qualify a candidate for licensure.
Confirm with your state board which exam it accepts before you register.
Frequently asked questions
Sources
- ADEX Dental Candidate Manual, Clinical (PDF) (opens in a new tab)
- ADEX Candidate Guide (PDF) (opens in a new tab)
- ADEX Dental Examination page (opens in a new tab)
- ADEX: CDCA-WREB-CITA and ADEX merger announcement (opens in a new tab)
- ADEX acceptance map (opens in a new tab)
- CRDTS Dental examination page (opens in a new tab)
- CRDTS Dental Examination Overview, Policy and Procedures (PDF) (opens in a new tab)
- CRDTS home page and portability map (opens in a new tab)
- CRDTS: SRTA merger page (opens in a new tab)
- ADA Student Licensure Overview (opens in a new tab)
Exam details change every season: confirm them with each agency and with your state board before you register.