___ is a VERY POOR CONDUCTOR - ANSWER-wax
______ acts as a NATURAL INSULATOR - ANSWER-Dentins
_______ and ________ are very brittle materials - ANSWER-enamel
porcelin
A change in temperature can result in an ___________ or _______ change in the dimension of a
material - ANSWER-immediate
delayed
a force that pulls an object apart? - ANSWER-Tensile
a force that slides the top of an object over the bottom? - ANSWER-Shear
a force that squeezes an object together? - ANSWER-Compressive
a material's response to a force, p.s.i.? - ANSWER-Stress
a material's ultimate strength is almost equal to its elastic limit. If a material easily breaks/fractures
under tensile force, the material would have low ductility and be considered brittle. i.e ceramic cup.? -
ANSWER-Brittleness
A POOR CONDUCTOR IS A ____ INSULATOR - ANSWER-good
a value of permanent strain (deformation). The stress where a material begins to function in a plastic
rather than an elastic manner. Some permanent strain (deformation) has occurred? - ANSWER-Yield
strength
ability of a material to withstand permanent deformation under tensile force/stress without breaking. If
a material can withstand a great deal of deformation under tensile force without breaking, the material
is referred to as DUCTILE. Gold is a very ductile material.? - ANSWER-Ductility
amount of energy absorbed by a material when it permanently deforms. Determined by calculating the
AREA UNDER THE LINEAR OR ELASTIC (straight line) portion of the stress-strain curve (mouthguard)? -
ANSWER-Resilience
Are ceramics radiolucent or radiopaque? - ANSWER-Radiolucent
Biologic is the effects on ______ tissue? - ANSWER-living
Brinell Hardness Test is used with what? - ANSWER-metals
Ceramics also include which 4? - ANSWER-Porcelain
glass
quartz
silica
Chemical is the ______ reaction? - ANSWER-setting
, Foundations test 4 DENTAL MATERIALS
Class 1 materials - ANSWER-least regulated i.e. prophy paste, brushes
Class 2 materials - ANSWER-approval of FDA i.e. composites, amalgams (seal of approval)
Class 3 materials - ANSWER-most regulated i.e. bone graft (pre-market approval)
Common composites are what type of mixtures? - ANSWER-are mixtures of polymer and ceramics
(esthetic, tooth-colored restorations)
deformation/change in dimension or shape of a material because of a force being applied. It tries to
resist the force. AS STRESS INCREASES, STRAIN INCREASES? - ANSWER-Strain
Dental metals _______ in warm, salty, acidic environments - ANSWER-corrode
Deterioration that only occurs on the SURFACE of a metal causing discoloration? - ANSWER-Tarnish
do metals appear radiopaque or radiolucent on radiographs? - ANSWER-Radiopaque
Each material that makes up a composite is called a _____? - ANSWER-Phase
Examples of metals are - ANSWER-orthodontic wires, partial denture clasps
Galvanism can create a ________ taste in the mouth - ANSWER-metallic
IF TWO OBJECTS (TOOTH AND A RESTORATION) HAVE DIFFERENT LINEAR COEFFICIENTS OF THERMAL
EXPANSION THEY WILL EXPAND AND CONTRACT AT DIFFERENT RATES AND AT DIFFERENT AMOUNTS,
EVENTUALLY RESULTING IN ___________? - ANSWER-microleakage
In metals _____ can slide by eachother - ANSWER-atoms
Is corrosion reversible or irreversible? - ANSWER-irreversible
Is it diamonded shaped or ball indenter? - ANSWER-Ball indenter
Is tarnish reversible or irreversible? - ANSWER-reversible
Is the Brinell used with rubber material? - ANSWER-no it is not used with rubber materials
is the primary bond weak or strong? - ANSWER-Strong
is the secondary bond weak or strong? - ANSWER-Weak
Leakage of oral fluids at the tooth/restoration interface results in: - ANSWER-Increase stain and
discoloration along the margins of a restoration
RECURRENT CARIES
Pulpal irritation/inflammation resulting in sensitivity
Materials with coefficients of thermal expansion similar to enamel and dentin include what 2 materials?
- ANSWER-golds and cements
maximum stress a material will withstand without permanent deformation. When stress is removed
from a material, the material completely recovers.? - ANSWER-Elastic limit