Prefabricated Crowns (e.g. 3M Iso-Form™ Crowns)
Advantages
Easy to use
Significant time savings over acrylic
Broad applications from short term to long-term coverage
Disadvantages
Limited to single units
Correct marginal adaptation of crown is critical
Acrylics (e.g., Jet by Lang, Snap by Parkell)
Advantages
Low cost
Esthetic
Versatile (either single or multiple units)
Disadvantages
Mixing required (powder/liquid)
Strong objectionable odor for patients and staff
A significant amount of heat is released during the setting reaction. This exothermic reaction has the potential to cause pulpal damage if not carefully controlled.
Difficult to repair
Significant waste/clean-up
High volumetric shrinkage (Methyl Methacrylates e.g. Jet)
Poor physical properties and color stability (R’Methacrylates e.g. Snap)
Composite Resin Systems (e.g. Luxatemp, DMG/Zenith)
Self-Cured Resin Materials
Advantages
Low odor
Minimal heat generation
Lower shrinkage than acrylic
Very good esthetics
Some systems use auto-mix delivery
Can be repaired using composite
Disadvantages
More expensive than acrylic
Many do not have an extended flexible stage
Viscosity cannot be altered
Different handling characteristics than acrylic
Resins form a sticky oxygen inhibited layer
Some materials are more brittle than acrylic
Multiphase Materials (e.g. 3M Iso-Temp Temporary Material)
Advantages
Automixed (no mixing or reloading of syringes)
Direct delivery to matrix
Operator control (extended working time in flexible stage)
Light cure on demand
Minimal odor, shrinkage and heat generation
Good wear resistance
Good esthetics
Multiple shades
Disadvantages
More expensive than acrylic
Viscosity cannot be altered
Resins form a sticky oxygen inhibited layer




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