Composite, Resins, and Glass-Ionomers Flashcards
What is a composite?
Hybrid material of an organic phase (resin) and an inorganic (filler) phase
Why do we use composites?
- Teeth are composites
- Advantages of both organic and inorganic components
- Easily processed and handled- allows for direct restorations
What are two ways to change crosslink density?
- Number of crosslinking groups
- Degree of crosslinking or degree of curing
What are the three types of curing?
Mixing (chemical), Heat, and light
What are the four components of composite resin?
Resin system, filler, bonding agent, and visible light initiator
What are the two components of the resin system?
- BisGMA-TEGDMA (most common)
- Structural component and dilutent
What does BisGMA stand for?
Bisphenol A glycidyl methacrylate (structural of main component)
What does TEGDMA stand for?
Triethylene glycol dimethacrylate
reactive dilutent
What are three characteristics of polymer bonds?
Covalent bonds, high molecular weight, and long molecules composed principally of nonmetallic elements (organic chemistry C,O,N,H)
What are the three classifications of resin fillers?
Micron (fine), nano (microfine), and nano (microfine) in polymer matrix
What is the loading weight of micron (fine) particles?
77-88 wt percent
What is the maximum loading weight of nano (microfine) filler?
38 wt percent
What is the loading weight of nano (microfine) in polymer matrix?
50-60 wt percent
What are the two effects of polymerization shrinkage?
Causes stress on the tooth structure and can cause microleaks and lead to secondary caries
What does water sorption do to composite restorations?
It works as a mechanism of degradation
