interum restorations Flashcards
interim restorations
fixed or removal dental prostheis diesgned for esthetics, stability or fucntion for a limited time to be replated by a definitive dental or maxillofacial prosthesis
side use of an interim restoration
determiniation of the therapeutic effectiveness of a specific treatment plan
do interim restorations have different goals vs perminant
no
ideal properties of provisional materials
Convenient handling: adequate working time, easy to mold, rapid set biocompompatable dimensionally stable ease of contour adequate strenth and abrasion resistnace good appearance good acceptability to patient easy to add or repair chemical caompatibility with interim luttin agent
interim materials
Acrylics (monomethacrylates) -polymethyl methacrylate -poly ethyl methacrylate Bisacryls (Dimethacrylates -BisGMA based -urethane dimethacrylate based
uses of mono methacrylates
Provisions
curstom trays
denture, RPD base
low end denture teeth
why use acrylics over bisacryls
cheaper
often used posterior
why use bisacryls over acrylics
look better
faster
more expensive
often used anterior
what is the intiator made of
2 componentes (SPO and AMine)
what does really fast propogation lead to
greater heat(methyl methacrylate creates 1,000,000 units a sec
how are monomethacrylates and dimethacrylates different chemically
Mono makes linear chains
di makes branched and crosslinked chains
characteristics of monomethacrylates
Tough and soft
characteristics of dimethacrylates
Brittle and Hard
how is the change in density of a polymer reaction found
through the shrinkage
how is shrinkage redued
through the addition of filler
why can’t you mix liquids and solids from different acrylic systems
initiator systems
what is found in the liquid of acrylics
MOnomers
inhibitors
chemical intiators (amine)
what is found in the powder of acrylics
Polymer beads
Colorants
Chemical initators (BPO)
what technology are bisacryl material based on
Composite tech (flowable)
Bisacryle are based on what chem
Dimethacrylates
characterisitcs of dimethacrylates
Higher moleculer weight monomers (oligomers)
silica fillers
reduced shrinkage
advantage of bisacryltes
good surface hardness good transverse strength easy to use low exothermic low shrinkage good margins good abrasion resistance minimal pulpal shrinkage good translucency and appearance better stain resistance and color stability
disadvantages of Bisacryltes
limited shades (but can layer with composite)
expensive
brittle
alteration and repair is hard
what is the ESF made of
polypropylene
how should the ESF be shaped
1-2 teeth on either side
1-2 mm beyond FGM
