+Non colored filling materials
Non colored (tooth colored) restoration materials have been used to replace missing tooth structure and to modify tooth color and thus enhancing facial esthetic.Types
1 Silicate filling material (silicate cement).2- Resin based filling material
a-Acrylic resin.
b-composite materials.
Silicate filling materials
The first colored restorative materials was used is silicate cement. It was used extensively to replace carious teeth for the anterior region. It has a good appearance, and available in a variety of tooth-like shade that help in close matching with surrounding tooth substance. It was supplied as powder and liquid system. The powder is sodium aluminosilicate glass with calcium fluoride. The liquid is a buffered, aqueous solution of phosphoric acid. The setting reaction is slow, during early stage the material is sensitive to the moisture , the filling materials should be protected from moisture by coating the surface with layer of varnish.Advantages
Fluoride release.Good thermal insulator
Coefficient of thermal expansion near to that of tooth structure.
Disadvantages
Erosion.Acidity.
Poor mechanical properties.
Need mechanical retention with tooth structure.
Resin filling materials
acrylic resin :
The self cure acrylic resin (chemical activated) for anterior restoration was developed to over come the problem associated with silicate cement. It supply as a powder and liquid . The composition is similar to that for denture base materials.
Advantages
Less prone to erosion and lower solubility as compared with silicate cement.Less acidity as compared with silicate cement.
Less brittle as compared with silicate cement.
Have good thermal insulation.
Have ability to match the appearance of tooth substance, but they have a tendency to discolored gradually with time
Disadvantages
Residual monomer.
Exothermic reaction.
Setting contraction.
High coefficient of thermal expansion.
Poor mechanical properties.
b.composite filling materials
in an effort to improve the physical characteristics of unfilled acrylic resins, a polymeric dental restorative material reinforced with silica particles was developed. Composite are resins reinforced by filler. The type, shape, size and amount of filler have significant effect on the mechanical properties of composite.The filler significantly enhance the physical properties of the composite by;
Increasing the strength.
Reducing the coefficient of thermal expansion.
Reduce polymerization shrinkage.
Lowe water sorption.
Increase wear resistance.
Improve color stability.
Gives good color matching.
Classification of Composite filling materials
Classification according to the method of activation.
Chemical cured.
Light cured.
Ultra violet light cure.
Visible light cure.
High intensity light cure.
Light emitting diodes.
Dual cured.
Classification according to the mean particle size of the major filler.Conventional composites.
Microfill composites.
Hybrid composites.
Advantages
Good Esthetic.Insulative, Low thermal conductivity.
Conservation of tooth structure removal.
Reparable.
Disadvantages
More difficult, time consuming and costly.
Technique sensitive.
High coefficient of thermal expansion.
Discoloration.
Have no good bonding with tooth substance(chemical and mechanical means of retention).