is a mixture of two or more materials that has properties superior to any single component
Composite
Composite is composed of mainly
organic (polymer) and Inorganic 9silica) joined together by a silacone coupling agent
What gives the material color of composite
pigment
The most comonly used resin for the matrix of composites are
bis GMA
Another used resin for the matrix of composite is
urethane dimethacrylate
Resin composites are ______liquids made up of two or more organic molecules
thick
To reduce the viscosity and allow the loading of filler particles, a what is added
low molecular weight monomer is added
What is added to the organic resin to make them stronger
Filler Particles
Fillers help to reduce
shrinkage
what helps reduce shrinkage
fillers
Fillers that are used in composit resins are made up of
inorganic particles
What are the inorganic fillers that are used in composite resins?
quartz, silica and glass
The higher the filler content the
stronger the material will be
What is an important factor to keep in mind when choosing a compsite resin material?
The size of the filler particles
Particle size will affect the ______ and _______ of the material .
wear resistance and polish ability
The amount of filler resin and the amount of resin between particles are related to how the material
wears
Large filler particles tend to get plucked from the resin matrix at the surface when the restoration is under
function
What cause the finished resteration to appear dull
Large Particles
Large particles cause the finished restoration to appear
dull
What particles are not as easily pulled from the resin and cause fewer voids that contribute to wear?
Smaller particles.
The smaller the particle the
smoother the surface
What makes a smooth surface?
smaller particles
What is used to provide a stronger bond between organic fillers and the resin matrix
coupling agent
what kind of coupling agent reacts with the suface of the inorganic filler?
Salane
What is necesseary to minimize loss of filler particles and reduce wear
Good adhesion
Good adhesion is necessary to
minimize loss of filler particles and reduce wear
What is the chemical reaction that occurs when low molecular weight molecules called monomers join together to form long chain of high molecular weight molecules called polymers
polymerization
What are low molecular weight molecules called
monomers
What are high molecular weight molecules called
polymers
Chemicals that cause polymerization reaction to begin are
initiators and activators
What are the three types of composite materials used in dentistry?
chemical, light and dual cure
Chemically cured also known as
self cure
A two paste system is
chemically cured/selfcured
What type of composite materials are stored in jars and syringes
chemical cured
In chemical/self cure one paste is called ____while the other is called_______
base, catalyst
There is limited work time with what material
chemical cure/ self cre
When chemical cure self cure the materials are mixed together to be spatulated in what kind of mixture to allow a thorough cure
homogenous
What can cause a void in chemical self cure restoration
air
What are the most common type of composite in dentistry cure wise
light cure
Which type of cure has ample working time
light cure
The material with light cure is in the ______wavelength
blue
dual cure has both _______ and _____
chemical and visible
these are two paste system that can be dispensed from syringe
dual cure
T/F composite resin have steadily improved in quality over the years
T
What three classifications are fillers available
Macrofilled, Microfilled, hybrid
Which filler classification is not used much anymore
macrofilled
which filler classification is for posterior strength?
hybrid
What is the first generation composite resin material?
Macrofilled
Which filler classification absorbs stain easily and has dualer surface and greater strength
Macrofilled
Which filler product does not absorb stain easily//
Microfilled
Microfilled is not as strong as Macrofilled T/F
T
Which filler product is easy to polish, high wear resistance
Hybrid
which are combination of small particles and microfine particles and are newest generation?
microhybrids
Flowable composites are ____________viscosity
low
These are utilized in deep pockets and conservative procedures
flowable composites
What is used to prevent caries
sealants
Do pit and fissure sealants use filler?
little or no filler
Sealants are similiar to
flowable composites
What is reduced when the tubules are sealed by dentin bonding agents or a base is placed?
sensitivity reduced
What causes pulpitis or inflamation
when composite resins release chemicals pass through dentinal tubules into the pulp
Composite with larger filler particles are stronger in both _____ and ________than they are microfilled materials
tensile and compression
Macrofilled composite material are still not as strong as
amalgam but they are stronger than glass ionomers
macrofilled composite material are not as strong as amalgam but are stronger than
glass ionomers
Composite wear faster than
amalgam
What is the term that refers to the shrinkage that occurs when the composite resin is cured
polymerization shrinkage
The matrix when cured usuallly shrinks away from the ____________-wall
cavity
What shrinks away from the cavity wall
matrix
Composite resin have a thermal conductivity close to that of
natural tooth structure
Composite resin is a biologically protective material for the
pulp
Idealy the coefficient of thermal expansion of the filling material would be the same as that of the
tooth structure
What can result in debonding and leakage of the restoration
coefficient thermal expansion
coefficient thermal expansion can result in
debounding and leakage of the restoration
What is the stiffness of the composite and is determined by the amt of filler
elastic modulus
The greater the volume of the fillerr the stiffer and more ____ resistant is a restoration
wear
What absorbs water from the oral cavity
resin
The greater the resin content the ___________ water is absorbed
more
What have greater water sorption
microfillers and flowables
microfillers and flowables have greater
water sorption
When water softens the resin matrix what happens to the aterial?
degrades
What metals are added to the filler to make the restoration more opaque when on xray?
lithium, barium, strontium
Lithium barium and strontium do what to fillers?
make radioopque
Older materials are they radiopaque?
no radiolucent for older materials.
Stress bearing areas like molars use what strong materials
hybrid or microhybrid
What are selfcured light cured tooth colored flouride releasing cements that bond to tooth surface
glass ionomers
Where are glass ionomers used
in cement crown, bridge veneers ortho also liner base or core
Hybrid ionomers are glass ionomers that have had ___________added to them to improve physical properties of glass ionomers
resins
hybrid ionomers are they stronger or weaker than glass ionomers?
stronger easier to polish and more wear resistant
What are componmers?
composite resins that have been modified with polyacid
What has been modified with poly acid
componmers
Do compomers release flouride?
yes
Examples of indirect restorations
inlays onlays veneers crowns with porcelain ceramic facings
what are indirect restorations
fabricated outside mouth