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what is the most common type of composite resin used in a private practice?
light cured
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what are 2 advantages of of the dual cure (2-paste system) polymerization?
- curing light initiates setting reaction
- chemical setting rxn continues in areas where light cannot be reached
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light cured composite resin is preferred because:
- there is no mixing needed
- cured when the operator is ready
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is macrofilled composite used today? what um is it? is it easy or hard to polish? does it get rougher with age and function?
- macrofilled is NOT used today
- 10-100um
- hard to polish
- rougher with age and function
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t/f microfilled composites make for large surface area (many small vs few large)
TRUE
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what is the filler volume of microfilled composites? are they weaker or stronger? more or less wear resistant
- 35-50% (others are 70-85)
- weaker
- less wear resistant
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t/f large particle composites are replaced by hybrid composites for posterior restorations
FALSE. small
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hybrid composites consist of ____ and ____ fillers
micro and macro
-
hybrid composites are ____ and _____ well
strong and polish well
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what is the filler content of hybrid composites?
75-85% by weight
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what is the particle size of microhybrid? filler content?
-
what have a particle size of .005-.02 um, shrinkage reduced from 3% to 1%, strong, and high shine?
nanohybrids
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flowable composites have ___ viscosity
low (how low can ya flow)
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particle size of flowable composite is ___-___um and has ___ adaptation to tooth walls
-
t/f flowable composites are not used in conservative dentistry
false! great in conservative dentistry
-
what is a preventative resin, used for sealants, class V non carious lesion, and as a liner?
flowable composites
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what has higher shrinkage, more wear, and weaker than a hybrid?
flowable composite
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t/f flowable composite is an excellent choice for areas of high occlusal function or high wear
false i say! not bloody likely!
-
can fillers be high to low in sealant material?
why yes
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highly viscous resins contain high volume filler particles in _______ composites
packable
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what are stronger and more wear resistant than hybrids, and shrink less on polymerization (more filler/less resin)?
packable composites
-
what is a smart composite?
- good for poor oral hygiene patient
- remineralizes the tooth
- there is no clinical study to confirm effectiveness....just a nice idea
-
smart composites release: (3)
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core-build up composites can be: (3) what type of cured?
light, self, or dual
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what are the advantages of composite provisional restorations vs acrylic? (4)
- wear less
- shrink less
- less heat as cured
- repaired easily with flowable composite
-
what are three disadvantages of a composite restoration vs an acrylic restoration?
- more expensive
- more brittle
- break more easily in longer span bridges
-
chemicals released from new deep composite resins can enter dental tubules and into pulp.. what is this called?
biocompatibility
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which composite is able to be used for anterior and posterior restorations?
hybrid
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which is more wear resistant, a sealant or flowable composite? why?
- flowable composite
- it has more filler particle content
-
t/f the lower the elastic modulus, the more flexible the material. the higher the elastic modulus, the stiffer the material
true
-
which shrink more when polymerized? hybrid or flowable?
flowable about 5 to 7%
-
t/f chemicals released from new deep composite resins can enter dentinal tubules into the pulp and cause an inflammatory rxn
true
-
t/f when the tubules are sealed by a dentin bonding agent or protected with a base or liner, there is no chemical entering the dentinal tubules
true
-
can someone be allergic to a certain composite resin material?
yes, anything is possible, just put your mind to it and you can do it
-
larger filler particles = stronger, tension, compression. is this correct?
probably....the answer is yes and i am tired
-
are microfills weaker than macrofills?
yes
-
does composite or amalgam wear faster?
composite
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what affects the wear rate of composite?
filler content
-
does more filler = better wear?
yes, more is better for shizzle
-
t/f microfills and flowables wear faster
true
-
with a chemical cure, where does it shrink?
toward the center of the bulk of the composite
-
does light cure shrink toward the center of the bulk of composite like chemical cure?
yep
-
t/f light cured resin shrinks towards the light
false! towards the center of the bulk of the composite
-
t/f with smaller increments there is less polymerization shrinkage
true
-
post insertion sensitivity= ______ increments (leakage)
larger
-
larger increments of composite placement results in what ?
- leakage
- tension on cusps
- greater shrinkage (bigger is not always better)
-
thermal conductivity of composite should be close to _____ ______ _______
natural tooth structure
-
composite material should be _______ protective for the dental ______
-
the greater the filler content, the _____ the CTE or the greater the resin content, the _______ the CTE
- lower
- higher
- (CTE=coefficient of thermal expansion)
-
what type of content is the greater filler content = lower cte?
hybrid
-
what type of composite is the greater resin content= greater cte
flowable
-
_______ and _______ have higher CTE than hybrid or packable
flowable or microfilled
-
what is the young's modulus (elastic modulus) of composite? what is it determined by?
the stiffness which is determined by the amount of filler
-
the greater the volume of filler, the ______ the elastic modulus and more wear resistant the restoration
higher
-
t/f the elastic modulus is an important consideration for selection of the type of composite
true
-
microfilled and flowable composites have fewer ________ and more ______
- fewer particles
- more resin
- (better for non-stress bearing restorations)
-
for a CLV restoration, what type of material is needed. stiff or flexible?
FLEXIBLE for all the flexion (esp because abfraction occurs due to the forces of the tooth flexion)
-
t/f resin matrix absorbes water over time
true
-
if there is a greater resin content, then more OR less water will be absorbed?
more
-
t/f microfills and flowables absorbe more water
true
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