Chapter 5 Direct Polymeric Restorative Flashcards
What are polymers?
Materials that are made of large, long molecules formed by chemically reacting molecules.
Within Polymers what are those molecules that are formed by chemical reaction called?
Monomers
What are the two types of polymers?
thermoplastic and thermoset
What are thermoplastic?
- can be heated and shaped, after ploymerization
- can melt
What are thermoset?
- final shape before polymerization
- Could decomposes
What are the different types of dental resins?
Acrylic resins
Composite materials
Glass lonomer materials
Compomers
Most dental resins are?
Thermoset
What are composite materials?
- A combo of 2 materials
- composed of 2 phases: matrix and filler
What is a matrix?
- bis-GMA
- organic chemical calledd diluent is added to control vicosity.
- weakest and least wear resistant phase of composite
- MAnufactors adds FILLER to increase strenght
Within matrix the organic chemical called diluent is added to what?
Control Viscosity
What are the positives and negatives of matrix?
- Positive- Polymerizes to form solid mass
- postivive- bonds to tooth structure
- Neg- weakest and least wear resistant phase
- neg- absorbs water, can stain
What is added to matrix to increase its strength?
Fillers
What are fillers?
enginerred glass materials
coated in silane coupling agent
How are composites classsified?
By their filler size
If filler contenet is increase then what occurs?
- reduces polymerization shrinkage
- increases hardness and abrasion resistance
What are macrofilled composites?
- Filler particles are large
- higher filler content
- feels rough to dental explorer
- plaque accumulation and staining
- mainly used in ortho
What is microfilled composites?
- Filler particles are small
- low filler content
- smooth similar to enamel
- used for esthetics
- Best for class V
What is hybrid composites ?
- mix of large and small filler particles
- high filler content
- high strength and abrasion resistant
- used in most areas of the mouth
What are glass Ionomer materials?
- release fluoride over time
- opaque
- mixed of powder and a liquid
- sets chemically
- poor wear resistance
- Most commonly used for Class V
What are resin- modified glass Ionomer?
- hybrid material of glass ionomer and resin
- light cured
- release fluoride
- stronger and tougher than glass ionomer
What are pits and fissures sealants?
- Preventive materials applied to pits and fissures
- composite material
- prevent or reduce caries
- can be placed by hygienist
What is enamel acid-etch?
- phosphoric acid
- allows material to bond to enamel
