Heat Cure Versus Cold Cure Partials

Heat Cure Versus Cold Cure Partials

Composition Of acrylic resin:

Heat Activated:

• Available as powder and liquid:
  • The powder may be transparent or tooth-colored or pink (to stimulate the gums some even contain red fiers to duplicate blood vessels).
  • The liquid is supplied in tightly sealed amber-colored bottoms (to prevent premature polymerization by light or UV radiation on storage).

“Role Of Curing Process In Partial Denture Quality”

• Liquid: 
  • Methyl methacrylate – Plasticizes the polymer
  • Dibutyl phthalate – Plasticizer
  • Glycol dimethacrylate (1–2%) – Cross-linking agent
  • Hydroquinone (0.006%) – Inhibitor-prevents setting.

“Best Ways To Understand Heat Cure Versus Cold Cure Partials”

“Importance Of Choosing Between Heat Cure And Cold Cure Partials”

• Powder:
  • Polymethyl methacrylate and another copolymer 5%
  • Polymethyl methacrylate beads – Major component
  • Ethyl or methacrylate (5%) – Copolymers improve properties
  • Benzoyl peroxide – Initiator
  • Compounds of mercuric – Dyes (color pigments) sulfide, cadmium sulfide, etc
  • Zinc or titanium oxide – Opacifirs
  • Dibutyl phthalate – Plasticizer
  • Fillers, inorganic particles like – Improves physical glass fiers, zirconium silicate, properties like alumina, etc. stiffness
  • Dyed synthetic nylon or – Stimulate small acrylic fibers capillaries

Chemically Activated Denture Base Resin

Composition Of Base Resin:

• Liquid: 
  • Methyl methacrylate – Dissolves/plasticizes/ monomer polymer
  • Dimethyl-p-toluidine – Activator
  • Dibutyl phthalate – Plasticizer
  • Glycol methacrylate – cross-linking agent.
  • Hydroquinone (0.006%) – Inhibitor

“Risk Factors For Failure Of Heat Cure And Cold Cure Partials”

• Powder :
  • Poly (methyl methacrylate) – Dissolved by and other copolymer − 5% monomer to form dough
  • Benzoyl peroxide – Initiator
  • Compounds of mercuric sulfide, cadmium sulfide – Dyes
  • Zinc or titanium oxide – Opacifirs
  • Dibutyl phthalate – Plasticizer
  • Dyed organic filers – For esthetics and inorganic particles like glass fibers or beads table

Composition Of Light Activated Acrylic Resin:

“Early Signs Of Problems With Heat Or Cold Cure Partial Dentures”

Mode of Polymerization of Denture Base Acrylic Resin

There are three types of modes of polymerization of denture base acrylic resin, i.e.

1. Heat Activated:
   • Here the mode of polymerization is by application of external heat for activation of polymerization reaction which is provided by water bath or by microwave.
   • Heat-activated resins are available in powder and liquid form.
2. Chemical Activated:
   • Here the mode of polymerization is by means of chemicals.
   • In this polymerization reaction starts as soon as powder and liquid components are mixed together.
   • Here activation of initiator benzoyl peroxide is done by chemical tertiary amine dimethyl-p-toluidine.

“Difference Between Heat Cure And Cold Cure Acrylic Resins”

1. Light Activated:
   • Here the mode of polymerization is blue light of wavelength 400 to 500 nm.
   • So as camphor quinone and organic amine come in contact with blue light of wavelength 400 to 500 nm they generate free radicals.
   • This activation of the photoinitiator initiates the polymerization reaction.
   • Light curing chamber consists of a rotating table over which the denture is placed so that it is exposed to uniform intensity of light.