Apr 25, 2024  
2022-2023 College Catalog 
    
2022-2023 College Catalog [ARCHIVED CATALOG]

DLT 202 - Dental Metallurgy

3 Credits, 3 Contact Hours
3 lecture periods 0 lab periods

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; electro-polisher and electrolyte solution operation; and safety procedures.

Prerequisite(s): DLT 101  and DLT 101LB .
Information: Consent of program director is required before enrolling in this course.


Course Learning Outcomes
  1. Make appropriate selections and safely manipulate dental alloys to meet specific restorative requirements.

Performance Objectives:
  1. Identify states of matter, as they relate to dental materials.
  2. Describe and demonstrate physical and mechanical properties of metal.
  3. Use specific gravity to calculate alloy requirements for a given wax pattern.
  4. Demonstrate using a troy system, weigh a casting and calculate the cost of the casting.
  5. Estimate the temperature of an alloy by color, starting at dull red.
  6. Describe processes used in the manufacture of dental alloys.
  7. List metals commonly occurring in dental alloys and how they affect the working characteristics.
  8. Explain the relationship of crystal structures to mechanical properties.
  9. Demonstrate methods of manipulating grain size in an alloy.
  10. Discuss how to relieve work hardening by annealing dental alloys.
  11. Perform calculations to compare carat, fineness, and percentage, for a given precious alloy.
  12. List the melt temperatures for pure gold and pure silver.
  13. Demonstrate the safe use of a casting torch.
  14. Describe a reducing and oxidizing flame and describe their affect on dental alloy.
  15. Demonstrate how to light a casting torch, adjust a reducing flame, and indicate the correct part of the flame for alloy melting.
  16. Compare and contrast the processes of electro-polishing and electro-plating.
  17. Describe the scrap refining process and how a laboratory would select a company to perform this service.
  18. List alloys that may contain metals that can cause allergies in some patients.
  19. List metals that are common causes of metal allergies.

Outline:
  1. Introduction to Dental Alloys
    1. American Dental Association (ADA) specifications
    2. Properties of matter
    3. Precautions for handling materials, hazardous substances, Occupational Safety and Health Administration (OSHA) regulations
    4. Safe use of laboratory equipment
  2. 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                   
  3. 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
  4. 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
  5. Equipment Calibration
    1. Melt temperature of pure gold
    2. Melt temperature of pure silver
    3. Temperature calibration procedures
  6. Metal Treatment and Torch Techniques
    1. Gas torch, burnout furnace, and centrifugal casting machine operation and safety procedures
    2. Oxidizing and reducing torch flames
    3. Flame zones
    4. Casting
    5. Soldering and welding
  7. Electro-Polisher and Electrolyte Solution Operation and Safety Procedures
    1. Cathodes
    2. Anodes
    3. Amperage
    4. Metal removal and deposition plating vs. polishing
  8. 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