Biological - Tissue derived materials - Skin, Bone, Cartilage

Replacement Materials - Synthetic materials - metals ceramics polymers

Oral Tissues as biological materials:

Denamel

Dentin

Cementun

Pulp

Alveolar Bone

Periodontal Ligaments

Gingiva

Restrictions on materials:

Bite forces,

Degradation Ex. Salvia,

Temperature Ex = 98.6,

Esthetics Ex. Amalgam vs composite,

Biocompatibility Ex. Allergies

“Whats the material going to do to my body, and what’s my body going to do to the material?”

Standard for Dental Materials:

American Dental Association (ADA)

Council on scientific Affairs

• Develops standards and guidelines for evaluating dental products. This includes: Pharmaceuticals, Materials, Instruments, Equipment
• Successful Evaluation of any of these categories is awarded the ADA’s seal of acceptance
• Dental products are NOT required to have the seal of acceptance to be marketed

Food and Drug Administration (FDA):

Medical device amendments of 1976

• The Fed. Gov. has the authority to regulate all things considered medical devices following the medical device amendments of 1976

Medical devices are placed into 3 categories:

Class I - Least regulated, only manufacturing practices are monitored ex. Toothbrush prophy paste, dental burs

Class II - Must meet performance standards such as standards set by ADA. Ex. Composite and amalgam (Tested but not heavily)

Class III - Heavily regulated, clinical data must be shown proving efficacy and safety. Ex. Bone graft and denture adhesive

International Standards Organization (ISO)

The ISO attempts to unify standards amongst countries that recognize the organization

THe guidance for regulation of dental materials is developed by the federation dentaire internationale (international equivalent to the ADA)

Classification of Dental Materials by use:

Restorative - Materials used to replace tooth structure

Temporary - Materials used to protect the tooth so that treatment can be finalized in the future

Cements - Materials used as luting agents, bases, outliner

Impressions, casts, models - Materials used to make replications of oral cavity

Polishing - Abrasive agents used to remove debris, clean, and smooth the surface of teeth, restoration, and appliances

Classification of dental materials by location of fabrications:

Direct - restoration fabricated directly inside the oral cavity

Indirect - restoration fabricated outside of the oral cavity

Classification of dental materials by longevity:

Permanent restoration - restoration fabricated directly in the oral cavity

Interim Restoration - long term temporization

Temporary Restoration - restoration fabricated outside of the oral cavity

Properties of materials: Physical, Mechanical, chemical

Study these Def’s:

PHYSICAL

Coefficient of thermal expansion: The measure of the change in volume due to change in temperature

Density: The mass per volume of a material

Vapor pressure: Measurement of a material's tendency to become a gas

Melting and Boiling Point: The measure ranges in which a material will change state

Thermal conductivity: A material's ability to take on energy (heat)

Electrical Conductivity: The ability of a material to conduct electricity

Viscosity: A material's ability to flow (Thickness of liquid)

Solubility: the ability for a material to dissolve in a liquid (put sugar in a glass of water is dissolves)

Hardness: A material's resistance to scratching

Water sorption: Ability of a material to

MECHANICAL

Strain: Deformation of the material

Stress: Force applied to material per unit area

Types of stress: Compression, tension shear, torsion, bending

Elasticity: Ability of a material change and return to original shape