Dental Materials Flashcards

Flashcards for Dental Materials Lecture Review

Primary Bonds

Stronger bonds between atoms and molecules.

Secondary Bonds

Weaker bonds between atoms and molecules.

Ionic Bonds

Formation of ions through electrical attraction.

Covalent Bonds

Sharing of electrons between atoms.

Metallic Bonds

A 'sea' of electrons shared among metal atoms.

Amorphous

Atoms in a non-repeating pattern.

Viscosity

The resistance of a liquid to flow.

Thixotropy

Viscosity decreases under stress.

Density

A measure of the weight a material has compared with its volume.

Hardness

The resistance of a solid to penetration.

Stress

Develops within a material when a force is applied.

Ultimate Strength

The amount of stress placed on a material at the time it breaks.

Elastic Deformation

Material recovers from a deformation and returns to original state.

Elastic Limit

The stress point at which a material cannot return to its original shape.

Plastic Deformation

Permanent deformation of a material.

Yield Stress

The stress point at which plastic deformation begins.

Elasticity

The measure of a material to recover its shape completely after deformation from an applied force.

Stiffness

Resistance to deformation.

Ductility

The amount of dimensional change it can withstand without breaking under tensile stress.

Malleability

The material responds easily to compressive stress.

Toughness

Ability of a material to absorb energy without fracture.

Resilience

Amount of energy a material can absorb without permanent deformation.

Fatigue

Occurs when a material is subjected to repeated stress, leading to sudden failure.

Durability

Ability of a material to withstand damage due to pressure and wear.

Corrosion

The most common electrochemical property seen in the oral cavity.

Metals

Have properties such as strength, ability to conduct electricity and heat, malleability, ductility, and luster.

Ceramics

Generally rigid and brittle and melt at high temperatures; poor conductors of heat and electricity.

Polymers

Can be flexible, easily shaped, and rubbery but also rigid and difficult to mold.

Direct Restorative Materials

Amalgam, composite, IRM

Indirect Restorative Materials

Crowns, veneers, bridges.

Permanent Restorative Materials

Long lasting replacement (amalgam, composite, PFM crown).

Temporary (provisional) Restorative Materials

Used for a short period of time (acrylic temporary crown).

Intermediate Restorations

Short time, but longer than temporary restorative materials (IRM)

Chemical Set Materials

Materials that set through the timed chemical reaction of the catalyst and base.

Light-Activated Materials

Materials that use a blue light source to initiate the reaction stage.

Dual Set Materials

Materials that begin with the initiation of the blue light source and then continue with a chemical set reaction.

Initial Set Time

Begins when the material no longer can be manipulated in the mouth.

Final Set Time

Occurs when the material has reached its ultimate state.

Job-Related Hazards in Dentistry

Exposure to particulate matter, mercury, chemicals, airborne contaminants, and biological contaminants.

Ways Chemicals Enter the Body

Inhalation, direct contact, absorption, ingestion, invasion through skin breaks.

Particulate Matter

Can be generated during the manipulation of many dental materials, especially dry, powdered materials.

Bio-Aerosols

Cloudlike mist containing microbes such as bacteria, viruses, molds, fungi, and yeast.

Hazardous Chemical

Chemicals shown to cause a physical or health hazard.

OSHA Hazard Communication Program Components

Written hazard communication program, chemical inventory, Safety Data Sheets (SDSs), labeling of chemical containers, employee training.

Chemical Toxicity Classification

Chemical toxicity classified by length of exposure, dose, and frequency of exposure.

Personal Chemical Protection

Hand protection, eye protection, protective clothing, inhalation protection.

Chemical Storage Precautions

General storage precautions, including noting expiration dates.

Criteria for Hazardous Waste Classification

Ignitable, corrosive, reactive, toxic.

Elastic Deformation

Material recovers from a deformation and returns to original state.

Elastic Limit

The stress point at which a material cannot return to its original shape.