Introduction
Composite cements, also called resin cements, are composite materials made for luting fixed prostheses. They are especially suited to translucent, metal-free ceramic restorations, because they come in different shades.
Composition
They contain the same basic components as composite filling materials, but with much less filler, so that they flow into a thin layer.
By setting reaction, they are chemically cured or dual-cured. By adhesive system, they use etch-and-rinse adhesives (three or two steps) or self-etch adhesives.
Commercial forms
- Syringes, for hand dosing and mixing
- Double syringes, with automatic dosing and hand mixing
- Double syringes with a mixing tip, for automatic dosing and mixing
- Capsules, mixed in a machine
Preparation
The two differently colored pastes are mixed by hand or automatically. The even color shows that mixing is complete. The tooth is first treated with the adhesive system that comes with the cement, following the manufacturer's instructions.
Properties
The high shrinkage comes from the low filler content. Biological tolerance depends on how much of the material polymerizes, because unreacted dimethacrylates and monomers are toxic to cells. These cements have no biological activity.