Midterm Exam Flashcards
positive copt of structure that results when stone is poured into an alginate impression
cast
used for a restoration or appliance fabrication
cast
completed stone casts are used to study the size and position of intra-oral tissues
model
used to treatment plan and observe treatment progress
model
a working replica of a single tooth
die
restorations that are constructed directly in the oral cavity
direct
are composites and amalgams direct or indirect
direct
are glass ionomers and other cements that set while in the mouth direct or indirect
direct
materials fabricated outside of the mouth
indirect
are crowns, inlays, and onlays direct or indirect
indirect
Evaluates dental drugs, materials, instruments, and equipment
ADA
successful evaluation of dental drugs, materials, instruments, or equipment
ADA seal
is the ADA seal required for dental products
no
has the authority to ensure safety of all medical devices
FDA
least regulated, only good manufacturing is required (prophy paste and brushes)
class I medical device
gain FDA approval after being shown to be equivalent to products currently in use (composite and amalgam)
class II medical device
most regulated; require premarket approval by the FDA (bone graft material)
class III medical device
approved products are marked with a certain symbol on their packaging from this group
ISO
what are the three medical device categories
use, location of fabrication, and longevity of use
materials used to replace lost tissue
restorative materials
restorative material that simulate the appearance of what they are replacing
esthetic materials
what are the three longevity of uses
permanent, temporary, or interim
ability of a material to absorb energy without becoming deformed
resilience
the ability of a material to resist destruction under the action of external force
strength
the force that develops in a loaded object
stress
pushing/crushing stress
compression
pulling stress
tension
sliding stress
shear
twisting stress
torsion
compression + tension stress
bending
change in length divided by original length
strain
results when an electron is given up by an atom and accepted by another
ionic bond
when two atoms share a pair of electrons
covalent bond
the result of partial charges from an uneven distribution of electrons
secondary bond
what are the types of secondary bonds
permanent dipoles
hydrogen bonds
fluctuating dipoles
weak bond by they have a significant effect on the behavior of many materials
permanent dipoles
strongest secondary bond
hydrogen bonds
weakest secondary bond
fluctuating dipoles
sharing many electrons by all the atoms in the material
metallic bond
a type of colloid made of two liquids that do not blend
emulsion
a liquid mixture which the solute in uniformly distributed within the solvent
solution
abrasion resistance; the ability of a material to resist scratching or indentation
hardness
amount of energy required to melt a material
heat of fusion
a measure of change in volume in relation to change in temperature
coefficient of thermal expansion
amount of energy needed to raise the temperature of a material
heat capacity
rate of heat flow through a material
thermal conductivity
the contraction of a gel accompanied by the separating out of a liquid
syneresis
measure of liquids ability to flow
viscosity
the absorption of one substance by another
imbibition
reaching gel state
gelation
increase wetting and reduce bubbles in the stone when the impression is poured up
surfactants
rotating the bowl in one hand and pressing the spatula flat against the side of the bowl
spatulation
motion used during spatulation
stropping
melting and gelling at different temperatures
hysteresis
viscous liquid state
sol
amount of material that is in a liquid such as water
solubility
the ability of a material to expand from its original shape when a force is applied, and ability to contract back into that shape when the force is released
elasticity
the time from the beginning of mixing the powder with water until material hardens
mixing time
length of time from the start of the mix until the setting mass reaches a semi-hard stage
working time
length of time from the start of the mix until the setting mass becomes rigid and can be separated from the impression
setting time
what are the types of inelastic impression materials
plaster
wax
zinc oxide eugenol
what are the types of aqueous elastomeric impression materials
alginate and agar
irreversible hydrocolloid
algiante
how does alginate set
chemical reaction
reversible hydrocolloid
agar
how does agar reach gelation
temperature changes
what are the types of non aqueous elastomeric impression materials
polysulfides
condensation silicones
polyethers
and addition silicones
what is the by product of polysulfides
water
what is the by-product of condensation silicones
alcohol
how do addition silicones set
addition polymerization
how do polyethers set
cationic polymerization
how do condensation silicones set
condensation polymerization
how do polysulfides set
condensation polymerization
what has surfactants added to them
addition silicones
speeds up reaction; warm water; potassium sulfate
accelerator
slows down reaction; cooler water; borax
retardeer
gypsum is a mineral ground and heated to drive out water particles through a process called _________
calcination
what’s the weakest type of gypsum
plaster
what type of hemihydrate is plaster
B
what type of hemihydrate is stone
A
what type of hemihydrate is improved stone
A
what is the measurement for improved stone
19-24 ml/100g
what is the measurement for stone
28-30 ml/100g
what is the measurement for plaster
45-50 ml/100g
the thickness of composite that is cured by a light source
depth of cure
placing dental composite in layers so that we can get adequate polymerization
incremental addition
what is the filler of macrofilled composites
quartz
what is the particle size of macrofilled composites
10-25
what percent weight and volume is the filler content of macrofilled composites
70-80% weight and 10-15% volume
what is the filler in microfilled composites
silica
what is the particle size in microfilled composites
0.04
what is the filler content weight of microfilled composites
40-50% weight
what are microfilled composites used for
esthetics
what is the particle size of hybrid composites
0.6-1
what is the filler content weight of hybrid composites
75-80% weight
what type of composites are strong and abrasion resistant
hybrid
what class restorations are hybrid composites used for
III or IV
lower filler content = lower viscosity = more flowable
flowable composites
will stick to dentin before light cured
flowable composites
