denture base resins Flashcards
broad term used to describe natural or synthetic substances that form plastic materials after polymerization
resin
designating a colorless, pungent acid
acrylic
colorless, transparent solid
pure PMMA
denture base fabricated with POLY (methylmethacrylate) resins
acrylic resins
PMMA resins:
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1excellent esthetic properties
2adequate strength
3low water sorption
4low solubility
5non-toxic, low allergenicity
6easily repaired
7reproduces detail accurately
8simple molding and processing technique
PMMA resin ingredients:
liquid monomer
powdered polymer
plasticizer
initiator
pigments
PMMA
liquid monomer:
powdered polymer:
plasticizer:
initiator:
pigments
liquid monomer: methyl methacrylate
powdered polymer: polymethyl methacrylate
plasticizer: dibutyl phthalate
initiator: benzoyl peroxide
PMMA resin is a two-component system:
liquid monomer and powdered polymer
PMMA liquid:
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methyl methacrylate, glycol dimethacrylate- a cross-linking agent
hydroquinone- inhibitor for increased shelf life
PMMA powder:
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- PMMA beads
- pigments
- plasticizer (dibutyl phthalate)
- benzoyl peroxide - initiator of polymerization
used in fabrication of all denture bases
heat-activated denture base
thermal energy required for polymerization
heat at surface of resin is conducted away into investing medium, hence no porosity on surface of resin
internal porosity: monomer boils
this vaporization of the monomer affects the thick areas of denture base
internal porosity
other porosity.
irregular shape, located throughout the base:
inadequate pressure, not enough resin in mold, improperly mixed resin
basically the same composition as the denture base resin, except for pigmentation to produce tooth shades
resin denture teeth
are highly cross-linked resins. TEETH and base chemically bond to each other
resin denture teeth
an amine in the liquid reacts with the benzoyl peroxide in the powder to promote polymerization at room temperature
autopolymerized resins
what is the difference between heat-activated and autopolymerized
method of activation of the initiator benzoyl peroxide
a greater degree of polymerization with
heat activated resin
better color stability with
heat activated resin
_______ in the liquid oxidizes and turns orange after a few mouths with the color stability of autopolymerized
teritary amine activator
