UDLT 104 - Dental Metallurgy

Students will develop enhanced understanding of the Dental Laboratory Technology profession. Including an examination of metals currently used by the dental technician. Includes introduction to dental alloys (e.g. physical and chemical properties); weights, measures, and calculations; metal sensitivities and allergies. Also includes alloy processing; equipment calibration; metal treatment and torch techniques; Laws of Casting; selective laser melt (SLM); electro-polisher and electrolyte solution operation; and safety procedures.

Prerequisite(s): DLT 101 and 102, or concurrent enrollment

Course Learning Outcomes:

Identify states of matter as they relate to dental materias.
Describe and demonstrate physical and mechanical properties of metal.
Use specific gravity to calculate alloy requirements for a wax pattern.
Demonstrate a troy system, weigh a casting and calculate the cost of a casting.
Describe processes used to manufacture dental alloys.
List metals commonly occurring in dental alloys and how they affect the working characteristics.
Explain the relationship of crystal structures to mechanical properties.
Explain methods of manipulating grain size in alloy.
Discuss how to relieve work hardening by annealing dental alloys.
Perform calculations to compare carat, fineness and percentage of an alloy.
List the melt temperatures for pure gold and pure silver.
Describe the safe use of casting torch.
Describe the Laws of Casting.
Describe a reducing and oxidizing lfame and effect on dental alloy.
Describe Selectie Laser Melt SLM 3D Printing
Compare and contrast electro-polishing and electro-plating processes.
List metals that are common causes of metal allergies.

Outline:

Introduction to Dental Materials
1. American Dental Association (ADA) specifications
2. Properties of Matter
3. Physical and chemical properties required for dental materials
4. Precautions for handling materials/hazardous substances/Occupational Safety and Health Administration (OSHA) Regulations, PPE, SDS
5. Safe use of laboratory equipment
Management of Materials
1. Inventory systems
2. Material storage
  1. Safety
  2. Shelf life
Impression Material
1. Identification and proper handling of various impression materials
  1. Agar hydrocolloid (reversible hydrocolloid)
  2. Rubber impression materials and elastomers
  3. Alginate
2. Impression trays
3. Disinfection of dental impressions, trimming, blocking out and re-disinfection
4. Model duplication
Gypsum Materials
1. Identification, application, and selection of gypsum material
  1. Plaster
  2. Articulating plaster
  3. Orthodontic plaster
  4. Hydrocal
  5. Laboratory stone
  6. Die stone
2. Manipulation and use of gypsum materials
  1. Powder water ratio
  2. Water temperature
  3. Setting expansion
  4. Preliminary set
  5. Final set
  6. Crush strength
  7. Crystalline structure
  8. Laminar flow, vibration, and the bubble-free model
3. Pouring study, preliminary, and working models
  1. Disinfecting impression material
  2. Trimming impressions
  3. Blocking out undercuts
4. Trimming poured casts
Dental Waxes
1. Identification and selection of dental waxes
2. Safe heating and use of dental wax
3. Correcting for wax discrepancies
  1. 1. Cooling contraction
  2. 2. Shape memory
VI. Refractory Materials
1. Identification and selection of refractory materials
  1. Casting investment
    1. Gypsum bound
    2. Phosphate bound
    3. Cristobalite
  2. Soldering investment
  3. Refractory dies
2. Manipulation of refractory materials expansion control
  1. Burnout temperature
  2. Powder water ratio
  3. Special liquid water ratio
VII. Resin
1. Identification and selection of acrylic resins
  1. Non-autopolymerizing acrylic resin
  2. Autopolymerizing acrylic resin
  3. Denture base resin
  4. Orthodontic resin
  5. Repair and reline resin
  6. Custom tray material
2. Manipulation of acrylic resin materials
  1. Salt and pepper technique
  2. Dough technique
  3. Pour technique
  4. Heat cure
  5. Microwave technique
  6. Injection molding
  7. Pressure pot cure
3. Compare and contrast analog resin techniques and 3D-printed resin
  1. SLA printing process
  2. Post-processing
  3. 3D Printer resin storage
  4. Waste resin and solvent disposal
Introduction to Dental Alloys
1. American Dental Association (ADA) specifications
2. IdentAlloy
3. Properties of Matter
4. Precautions for handling materials, hazardous substances, Occupational Safety and Health Administration (OSHA) regulations
5. Safe use of laboratory equipment
Physical and Chemical Properties of Dental Alloys
1. Hardness
2. Ductility
3. Malleability
4. Specific gravity
5. Elasticity
6. Elastic limit
7. Elongation
8. Grain size
9. Melt range
10. Fusion temperature
11. Deformation of metal
12. Annealing
Weights, Measures, and Calculations
1. Carat system
2. Fineness system
3. Percentages
4. Troy system
5. Metric system
6. Cost calculation
7. Wax to gold casting calculation
Alloy Processing
1. Manufacturing
2. Dental alloy scrap and refining
3. Characteristics of constituent metals and their effect on dental alloys
4. Melting alloy vs. pure metal
5. Visual estimation of metal temperature
6. Work hardening
7. Grain structure
8. Grain growth
9. Annealing
Equipment Calibration
1. Melt temperature of pure gold
2. Melt temperature of pure silver
3. Temperature calibration procedures
Metal Treatment, Torch Techniques, and Induction Casting
1. Gas torch, burnout furnace, and centrifugal casting machine operation and safety procedures
2. Oxidizing and reducing torch flames
3. Flame zones
4. Induction Casting
5. Laws of casting
6. Casting
7. Soldering and welding
Milling or reductive manufacturing
1. Design
2. Milling
3. Post process
  1. Waste
  2. Separation
  3. Machine work
Selective Laser Melt 3D Printing
1. Design
2. Print
3. Post process
  1. Cleaning up the residual powder
  2. Heat treatment
  3. Separation
  4. Machine work
Electro-Polisher and Electrolyte Solution Operation and Safety Procedures
1. Cathodes
2. Anodes
3. Amperage
4. Metal removal and deposition plating vs. polishing
Metal Sensitivities and Allergies
1. Metals commonly acknowledged as sources of allergies
2. Dental alloys that can contain allergy-causing metals
3. Alloy alternatives
4. Reactions of dissimilar metals in the oral environment