interum stuff Flashcards
what are Acrylics
Monomethacrylates
examples of Acrylics
Polymethyl methacrylate (Jet, Duralay) Polyethyl methacrylate (trim, snap_
what are Bisacryls
Dimethacrylates
examples of Bisacrylcs
BisGMA (provisa, Protemp) Urethane Dimethacrylate (Luxatemp)
use of Monomethacrylates
Provisions
Old styles custom trays
Dentures, RPD bases
Low end denture teeth (high end are interpenetated networks with crosslinking)
speed of Acrylic polymerization
FAst (generates lots of heat)
-1,000,000 units a second
difference chemically of Jet and trim
jet has a methyl group hanging off the ether
Trim has an ethyl group hanigng of the ether
Monomethacrylates for what type of chain
Linear chain
characteristics of Monomethacrylates
Tough
Soft
what type of chain do dimethacrylates create
Crnach and crosslinked
characteristics of Dimethacrelates
Brittle
Hard
what materials create linear chain
Jet and trim
what materials create branch and crosslinking
BisAcryl
how is the change in density realized for Polymer formation
Through shrinkage
what is done to reduce shrinkage
Adding fillers
what is in the liquid of acrylics
Monomers
Inhibitors
Chemical initiators (amine)
what is in the powder of acrylics
Polymer beads
Colorants
Chemical initiators (BPO)
what dictates the reason why you cannot mix systems
The initiator system (BPO and Amine need to mix correctly)
what are Bisacryls based on
based on Composite tech or Dimethacrylates
how do Bisacryls work
Flowable like composite
what makes up the Dimethacrylate of Bisacryls
High molecular weight monomers (oligomers
Silica fillers
reduced shrinkage
PRos of Bisacryls
Good surface hardness Good transverse strength Easy to use Low exothermic Low shrinkage Good margin fit Good abrasion resitnace Minimal pulpal iritation good translucency and appearance resist stain better color stability
cons of Bisacryl
Limited shades (layer with composite
Expensive
brittle (fracture when thin)
alteration and repair difficult
what are the ideal properites of interum material
Convenient handling (working time, rapid set time, easy modling) Biocompatibility Dimensional stability during set East of contour and polish Adequate strength Appearance Ease of repair
