Properties-Introduction Flashcards
Inlay
Restoration made to fit into a tapered cavity preparation
Crown
restoration that restores anatomy and function of part or all the coronal portion of tooth
Clasp
clawlike metal attachment of a partial denture that grasps the natural teeth
Denture
a removable prosthesis that replaces all the teeth of the upper or lower arch
Dimensional change
percent shrinkage or expansion of a material
Thermal Dimensional change
*Linear Thermal Expansion Coefficient
- subjected to temperature changes
* a measure of how much it expands per unit length if heated one degree higher
Thermal Conductivity
- measure of heat transferred
- high conductivity values = good conductors of heat and cold
Galvanism
- generation of electrical currents that the patient can feel
- when dissimilar metallic filings are present on opposing teeth; patient experiences pain during contact of filings
Corrosion
-dissolution(dissolved) of metals in mouth
Tarnish
-surface reaction of metals in mouth from components in saliva or foods
-Solubility and sorption
- in weight percent of soluble or sorbed material
- as weight of dissolved or sorbed material per unit of surface area
Sorption
adsorption + absorption
Adsorption
- when dissimilar materials are in intimate contact w/ each other, there’s no surface action
- no penetration of material from one surface into the other
Absorption
- substance particle usually penetrates surface of a solid surface
- refers to uptake of liquid by the bulk solid
Wettability
- low contact angle
- contact angle
-measure of the affinity(attractive force) of liquid for a solid as indicated by spreading of a drop
- solid is readily wetted by a liquid: hydrophilic
- is greater than 90 degrees: poor wetting ability
Stress
- Force per unit area
- Load/area e.g. pencil
Strain
*Elastic Modulus
- the change in length per unit length of a material produced by stress
- deformation per unit length
- is equal to the ratio of the stress to the strain in the linear or elastic portion of the of the stress strain curve
- a measure of stiffness of a material
Proportional limt and yield strength
-measures of stress allowed before permanent deformation
Ultimate strength
-stress at which fracture occurs
Elongation and Compression
-measures of ductility and malleability
Malleability
-ability of substance to be hammered or rolled into thin sheets without fracture
Ductility
-ability of a material to be drawn into wire under tensile strength
Resilience and Toughness
-indicate the energy absorbed up to the proportional limit and ultimate strength, respectively and relate to the resistance to deformation and fracture under impact
Hardness
-resistance of a material to indentation
