CDT study guide
CDT · Work through your exam, one topic at a time.
The Certified Dental Technician (CDT) credential is awarded by the National Board for Certification in Dental Laboratory Technology (NBC), which describes itself as "the independent board founded by the National Association of Dental Laboratories (NADL)." It is aimed at dental laboratory technicians who want to demonstrate "significant mastery of the knowledge and applied skills needed in dental technology" - a benchmark dentists and labs can check through NBC's public CDT directory. NBC also issues the CDL (certified dental laboratory) and RG (recognized graduate) credentials, and its examination program covers all three. The CDT study guide has 5 sections and about 1,832 words.
01Complete Dentures: Retention, Recording, and Occlusion
A complete denture replaces the entire dentition and its supporting hard and soft tissues, so success depends on three pillars: retention (resistance to vertical dislodgement, from adhesion, cohesion, atmospheric pressure and an intact border seal), stability (resistance to horizontal and rotational forces) and support (resistance to seating forces, from the denture-bearing area). You must be able to describe the impression sequence: primary irreversible hydrocolloid, border molding in a custom tray, then a wash of light-bodied material to capture the peripheral seal.
378 words, about 2 min02Removable Partial Dentures: Classification and Framework Design
RPD questions reward a disciplined sequence: classify the arch, survey the casts, then design a framework that protects teeth and residual ridges. Learn Kennedy Classes I–IV and Applegate's rules - the class is set by the most posterior edentulous area, missing third molars are not counted unless being replaced, and an edentulous area distal to a remaining tooth is included in the classification.
384 words, about 2 min03Crown and Bridge: Preparation Principles and Fixed Prosthesis Design
Fixed prosthodontics is governed by retention (resistance to withdrawal along the path of insertion), resistance (resistance to lateral and tipping forces), and structural durability . The classic preparation parameters are a total occlusal convergence of about 6–10 degrees, adequate occlusal reduction (roughly 1.5–2 mm on functional cusps, 1–1.5 mm elsewhere), and a defined finish line - chamfer for metal and metal-ceramic, shoulder or deep chamfer for all-ceramic.
349 words, about 2 min04Ceramics: Material Selection, Bonding and Failure Modes
Dental ceramics split into glass-rich materials (feldspathic, leucite-reinforced, lithium disilicate) and polycrystalline materials (zirconia, alumina). Glass-rich ceramics can be etched with hydrofluoric acid, creating a microretentive surface that is then coupled with a silane primer and resin cement.
352 words, about 2 min05Orthodontics: Diagnosis, Biomechanics and Retention
Orthodontic diagnosis combines growth assessment, model analysis and cephalometrics. Know the skeletal landmarks: SNA reflects maxillary position, SNB mandibular position, and ANB their relationship - an ANB above roughly 4 degrees suggests a skeletal Class II, a negative ANB a Class III.
369 words, about 2 min