CDT Examination Overview
These study notes are designed for candidates preparing for the Certified Dental Technician (CDT) examination, focusing on the core subjects of dental laboratory technology. The notes are based on official sources from the National Board for Certification (NBC) and the National Association of Dental Laboratories (NADL). They provide instructional content, key distinctions, and review tasks to help candidates understand the material and apply it in clinical and laboratory settings. Candidates should verify specific exam details (e.g., pass mark, format) with the official NBC website.
For Dental Conquer practice planning, this module is tracked as 80 questions over about 120 minutes with a listed pass mark of 70%. Treat those numbers as practice baselines and verify the current official format before scheduling.
How This Guide Is Organized
The sections below turn the syllabus into studyable subject blocks. Read a subject first, explain the must-know ideas without notes, then use questions and flashcards to test whether the knowledge holds under pressure.
- Dental Anatomy, Morphology, and Physiology
- Dental Materials Science and Properties
- Laboratory Safety and Infection Control
- Fixed Prosthodontic Framework and Design
- Removable Prosthodontic Principles
- Digital Dentistry and CAD/CAM Technology
Exam Snapshot and Readiness Target
Format: 80 questions, 120 minutes (practice baseline; verify with NBC)
Candidate level: Entry-to-practice for dental laboratory technicians
Readiness target: Competency in dental anatomy, materials, safety, prosthodontics, and digital dentistry
Most candidates should budget at least 38+ focused study hours, then adjust upward for unfamiliar clinical systems, regulatory content, or specialty-level case reasoning.
Dental Anatomy, Morphology, and Physiology
Syllabus Focus
- Tooth morphology and identification
- Occlusion and articulation
- Oral anatomy and physiology
Key Notes
- Understand the universal numbering system (1-32) and FDI notation for permanent and primary teeth.
- Know the anatomical landmarks of each tooth: cusps, ridges, fossae, grooves, and marginal ridges.
- Differentiate between maxillary and mandibular teeth, and between anterior and posterior teeth.
- Study the curve of Spee, curve of Wilson, and occlusal plane relationships.
- Understand the temporomandibular joint (TMJ) anatomy and its role in mandibular movement.
- Learn the basic principles of centric relation, centric occlusion, and maximum intercuspation.
- Recognize common anatomical variations and anomalies (e.g., dens evaginatus, talon cusp).
Must Know
- Tooth morphology: number of cusps, root structure, and eruption dates.
- Occlusal schemes: bilateral balanced, canine guidance, and group function.
- Mandibular movements: protrusion, retrusion, laterotrusion, and mediotrusion.
- Incisal and occlusal guidance angles.
- Differences between primary and permanent dentition.
Clinical and Exam Application
- Use tooth morphology to design crown contours and proximal contacts.
- Apply occlusal principles to adjust articulation for fixed and removable prostheses.
- Identify tooth anatomy when fabricating diagnostic wax-ups and provisional restorations.
High-Yield Distinctions
- Maxillary first premolar: two cusps (buccal and lingual), bifurcated root (often).
- Mandibular first premolar: small lingual cusp, buccal cusp dominant.
- Maxillary first molar: three roots, rhomboidal occlusal outline.
- Mandibular first molar: two roots, five cusps (three buccal, two lingual).
- Primary molars: more bulbous crowns, narrower occlusal tables, and divergent roots.
Common Pitfalls
- Confusing maxillary and mandibular premolars: note root morphology and cusp size.
- Misidentifying tooth numbers: practice with both universal and FDI systems.
- Overlooking the significance of the curve of Spee in articulation.
- Assuming all molars have three roots: mandibular molars typically have two.
Review Tasks
- Draw and label each permanent tooth from a buccal and occlusal view.
- Practice identifying teeth on mounted study models.
- Complete a chart of eruption dates for primary and permanent teeth.
- Review TMJ anatomy and mandibular movement diagrams.
Dental Materials Science and Properties
Syllabus Focus
- Physical and mechanical properties
- Gypsum products and investments
- Wax patterns and casting alloys
- Ceramics and polymers
Key Notes
- Understand key properties: strength, hardness, elasticity, thermal expansion, and creep.
- Know the setting reaction of gypsum: calcium sulfate hemihydrate + water → calcium sulfate dihydrate.
- Distinguish between Type I-V gypsum products based on strength and application.
- Learn the composition and uses of inlay casting wax, baseplate wax, and sticky wax.
- Study the classification of dental alloys: noble (gold, platinum), high-noble, and base metal (Ni-Cr, Co-Cr).
- Understand the firing cycle and shrinkage compensation for dental ceramics.
- Know the properties of impression materials: alginate, silicone, polyether, and polysulfide.
Must Know
- Gypsum setting expansion and its control (e.g., using accelerators/retarders).
- Thermal expansion coefficient of investment materials relative to casting alloys.
- Hardness scales: Mohs, Knoop, Vickers, and Rockwell.
- Elastic modulus and its relevance to framework rigidity.
- Porcelain-fused-to-metal (PFM) bond strength and metal preparation.
Clinical and Exam Application
- Select appropriate gypsum for study models (Type III) vs. dies (Type IV).
- Choose investment material based on casting alloy melting range.
- Apply wax pattern techniques for proper marginal fit and contour.
High-Yield Distinctions
- Type IV gypsum (die stone) has high strength and low expansion.
- High-noble alloys contain ≥60% noble metals (Au, Pt, Pd).
- Base metal alloys have higher hardness and lower cost but require careful handling.
- Ceramics: feldspathic vs. lithium disilicate vs. zirconia - different translucency and strength.
- Addition silicone (PVS) has better dimensional stability than condensation silicone.
Common Pitfalls
- Confusing setting expansion with thermal expansion.
- Using the wrong gypsum type for a specific application (e.g., Type I for dies).
- Overheating wax patterns causing distortion.
- Ignoring the coefficient of thermal expansion mismatch between ceramic and metal.
Review Tasks
- Create a table comparing gypsum types (I-V) with properties and uses.
- Calculate the amount of water needed for a given gypsum powder (W/P ratio).
- List the steps for investing and casting a metal framework.
- Review the composition and firing temperatures of common dental ceramics.
Laboratory Safety and Infection Control
Syllabus Focus
- OSHA and CDC guidelines
- Personal protective equipment (PPE)
- Hazard communication and waste disposal
- Infection control protocols
Key Notes
- Follow standard precautions: treat all patients and laboratory items as potentially infectious.
- Use appropriate PPE: gloves, mask, eye protection, and lab coat.
- Understand the OSHA Hazard Communication Standard (HCS) and Safety Data Sheets (SDS).
- Know proper disposal of sharps, contaminated waste, and chemical waste.
- Implement infection control for impressions: rinse, disinfect with EPA-registered disinfectant.
- Maintain clean and dirty zones in the laboratory.
- Regularly calibrate and maintain sterilization equipment (autoclave, dry heat).
Must Know
- Hand hygiene: wash with soap and water or use alcohol-based hand rub.
- Disinfection levels: low, intermediate, high (e.g., glutaraldehyde for high-level disinfection).
- Sterilization methods: steam autoclave (121°C, 15 psi), dry heat (160°C, 2 hours).
- Biological indicators (spore tests) for monitoring sterilization efficacy.
- Labeling and storage of hazardous chemicals.
Clinical and Exam Application
- Disinfect all incoming impressions and prostheses before handling.
- Use appropriate containers for sharps disposal.
- Follow spill cleanup procedures for mercury or other hazardous materials.
High-Yield Distinctions
- EPA-registered hospital disinfectant vs. tuberculocidal disinfectant.
- Critical, semi-critical, and non-critical items based on Spaulding classification.
- Autoclave vs. chemical vapor sterilization: advantages and limitations.
- Mercury hygiene: use of amalgam separators and proper storage.
Common Pitfalls
- Reusing disposable PPE or not changing gloves between patients.
- Improper dilution of disinfectants.
- Not allowing sufficient contact time for disinfection.
- Mixing incompatible chemicals (e.g., bleach and ammonia).
Review Tasks
- Review the OSHA Bloodborne Pathogens Standard and employer responsibilities.
- Practice reading an SDS for a common dental material (e.g., gypsum).
- Create a checklist for daily laboratory safety inspection.
- Simulate a spill cleanup procedure for a chemical or biohazard.
Fixed Prosthodontic Framework and Design
Syllabus Focus
- Crown and bridge design
- Margin types and preparation geometry
- Framework fabrication (metal, ceramic, zirconia)
- Connectors and pontic design
Key Notes
- Understand the principles of tooth preparation: retention, resistance, and structural durability.
- Know margin types: chamfer, shoulder, bevel, and knife-edge; indications and limitations.
- Learn the design of metal-ceramic (PFM) frameworks: metal thickness, ceramic veneer support.
- Study connector design for fixed partial dentures: embrasure shape, connector height and width.
- Understand pontic design: sanitary, ridge lap, modified ridge lap, and ovate.
- Know the criteria for abutment selection: crown-to-root ratio, periodontal health, and tooth position.
- Learn the use of surveyors for determining path of insertion and blockout.
Must Know
- Minimum occlusal clearance for metal-ceramic: 1.5-2.0 mm.
- Connector dimensions: at least 3 mm height and 3 mm width for posterior bridges.
- Retention and resistance form: taper (2-6 degrees), surface area, and axial wall height.
- Margin placement: supragingival, equigingival, or subgingival based on esthetics and caries risk.
- Framework try-in: fit, seating, and marginal integrity.
Clinical and Exam Application
- Design a three-unit bridge for a missing first molar: select abutments, design connectors, and choose pontic type.
- Evaluate a PFM framework for proper metal thickness and ceramic support.
- Use a surveyor to determine the path of insertion for a fixed partial denture.
High-Yield Distinctions
- Chamfer margin: preferred for metal-ceramic crowns; shoulder margin: for all-ceramic crowns.
- Sanitary pontic: easy to clean but less esthetic; ovate pontic: more esthetic but requires surgical site.
- Rigid connector: soldered or cast; non-rigid connector: precision attachment for tilted abutments.
- Zirconia framework: high strength, but requires careful design to avoid chipping.
Common Pitfalls
- Insufficient occlusal reduction leading to ceramic fracture.
- Over-tapering the preparation causing loss of retention.
- Connector too small leading to framework fracture.
- Ignoring the path of insertion causing binding or poor fit.
Review Tasks
- Draw a cross-section of a PFM crown showing metal and ceramic layers.
- Calculate the required connector dimensions for a given span.
- Practice surveying a cast for a fixed partial denture.
- Review case studies of failed fixed prostheses and identify design flaws.
Removable Prosthodontic Principles
Syllabus Focus
- Complete denture design and fabrication
- Removable partial denture (RPD) design
- Major and minor connectors
- Rests, clasps, and indirect retainers
Key Notes
- Understand the anatomy of edentulous ridges and supporting structures.
- Learn the steps for complete denture fabrication: impressions, jaw relation records, try-in, and insertion.
- Know the principles of RPD design: support, retention, stability, and bracing.
- Study the components of an RPD: major connector, minor connectors, rests, clasps, and indirect retainers.
- Understand the Kennedy classification for partially edentulous arches.
- Learn the design of major connectors: maxillary (palatal plate, strap) and mandibular (lingual bar, plate).
- Know the types of direct retainers: circumferential clasps, bar clasps, and combination clasps.
Must Know
- Posterior palatal seal: location and depth for complete denture retention.
- RPD design principles: guide planes, reciprocal arms, and bracing.
- Rest seat preparation: form and depth (1-1.5 mm for occlusal rests).
- Indirect retainers: function and placement (e.g., on canine or premolar).
- Major connector rigidity: must be rigid to distribute forces.
Clinical and Exam Application
- Design an RPD for a Kennedy Class II modification 1 arch.
- Select appropriate clasp design for an abutment tooth with a surveyed crown.
- Evaluate a complete denture for proper border extension and retention.
High-Yield Distinctions
- Kennedy Class I: bilateral distal extension; Class II: unilateral distal extension; Class III: unilateral bounded edentulous area; Class IV: anterior bounded edentulous area.
- Circumferential clasp: engages 180° of tooth circumference; bar clasp: approaches from gingival.
- RPI system: rest, proximal plate, I-bar - used for distal extension bases.
- Maxillary major connector: palatal plate for broad distribution; mandibular: lingual bar for minimal bulk.
Common Pitfalls
- Inadequate rest seat preparation causing rest fracture or tooth movement.
- Overcontouring major connectors causing tissue irritation.
- Incorrect clasp placement leading to poor retention or food impaction.
- Not accounting for tissue undercuts in distal extension RPDs.
Review Tasks
- Sketch a Kennedy Class III RPD design with all components labeled.
- Practice surveying a diagnostic cast for an RPD.
- List the steps for a complete denture try-in and adjustments.
- Review the differences between tooth-supported and tissue-supported RPDs.
Digital Dentistry and CAD/CAM Technology
Syllabus Focus
- Digital impressions and scanning
- CAD software and design principles
- CAM milling and 3D printing
- Materials for digital fabrication
Key Notes
- Understand the workflow: intraoral scanning → CAD design → CAM fabrication.
- Know the types of intraoral scanners: confocal, structured light, and laser.
- Learn CAD software tools: margin marking, occlusal adjustment, and sprue placement.
- Study CAM methods: subtractive (milling) and additive (3D printing).
- Know the materials used in CAD/CAM: zirconia, lithium disilicate, PMMA, and resin.
- Understand the sintering process for zirconia: pre-sintered vs. fully sintered.
- Learn the principles of digital smile design and virtual articulation.
Must Know
- Scanning accuracy: factors like powder, ambient light, and operator technique.
- Milling burs: types (diamond, carbide) and wear monitoring.
- 3D printing technologies: SLA, DLP, and PolyJet.
- Post-processing: cleaning, curing, and sintering.
- Digital workflow for implant restorations: scan bodies, library abutments.
Clinical and Exam Application
- Design a single crown using CAD software: set margin, adjust occlusion, and add cement gap.
- Mill a zirconia crown: select block size, milling strategy, and sintering schedule.
- Print a surgical guide for implant placement using DLP technology.
High-Yield Distinctions
- Pre-sintered zirconia: easier to mill but requires shrinkage compensation (20-25%).
- Lithium disilicate: high esthetics, etchable, used for anterior crowns and veneers.
- PMMA: used for temporary restorations and diagnostic wax-ups.
- SLA vs. DLP: DLP uses a digital projector for faster curing; SLA uses a laser for higher accuracy.
Common Pitfalls
- Incorrect margin marking leading to open margins.
- Not compensating for zirconia shrinkage causing misfit.
- Overmilling or undermilling due to improper toolpath settings.
- Poor post-processing (e.g., incomplete curing) causing material degradation.
Review Tasks
- Practice scanning a typodont model and evaluating scan quality.
- Design a simple crown in CAD software and export the STL file.
- Review the sintering cycle for a specific zirconia brand.
- Compare the advantages and disadvantages of milling vs. 3D printing for different applications.
How To Use These Notes With Practice Questions
Do not jump straight from reading to a full mock. Work by subject first: review the key notes, make a short recall sheet from memory, then answer a focused question set. After each miss, decide whether the problem was missing knowledge, poor clinical sequencing, weak source-rule recall, or a distractor you failed to eliminate.
Dental Conquer's question bank, flashcards, mind maps, and spaced review tools are most useful after this instruction layer because they reveal which parts of the notes are not yet retrievable.
Final Review Checklist
- Review all subject summaries and focus on high-yield distinctions.
- Practice identifying tooth morphology and occlusion on models or images.
- Memorize key material properties and their clinical implications.
- Understand infection control protocols and safety data sheets.
- Be able to design a fixed or removable prosthesis given a clinical scenario.
- Familiarize yourself with digital workflow steps and common CAD/CAM materials.
- Take practice exams under timed conditions to build speed and accuracy.
- Verify any uncertain details with official NBC resources.
Official Sources and Further Reading
Use these sources as the final authority for format, eligibility, rules, and exam updates. Study notes are a preparation layer, not a replacement for official candidate guidance.