Composite for posterior teeth:
a. Microfilled + fine filler.
b. Macroflled + rough filler.
c. Hybrid + rough filler. *** (hybrids are more resistant to wear than the conventional macrofilled)
Clinical Aspects of Dental Materials Theory, Practice, and Cases (3rd Ed 2009)
The strength and other physical properties, EXCEPT wear resistance and surface roughness, of macrofilled composites are adequate for Class III, IV, and V restorations. Excessive wear when used for Class I and II restorations limited their posterior use. Macrofills were used before dentinal bonding systems were developed; placing them in posterior teeth resulted in postoperative sensitivity, leakage, and recurrent decay.
The problem with microfilled composites is the low percentage filler (40–50%). The surface area of the very small filler particles requires much more resin to wet the surface of the filler particles. This high resin content results in an increased coefficient of thermal expansion and lower strength.
Microfilled composites were used when esthetics are the dominant concern. Large composite restorations, such as an extensive Class IV restoration, are built in layers of several different shades and translucencies. The first layers to be placed are a hybrid composite selected for strength. The final layer, a veneer of sorts, is a microfilled composite selected for surface luster.
Microfilled composites are also used in Class V restorations at the cemento–enamel junction. Microfills have a lower modulus of elasticity and flex with the tooth better than the strongest composite materials. Clinical research has shown Class V microfill composite restorations are more likely to be retained than other composite materials.
Hybrid composites are very popular; their strength and abrasion resistance are acceptable for small to medium Class I and II restorations. Their surface finish is nearly as good as that of microfills; thus, they are also used for Class III and IV restorations.
a. Microfilled + fine filler.
b. Macroflled + rough filler.
c. Hybrid + rough filler. *** (hybrids are more resistant to wear than the conventional macrofilled)
Clinical Aspects of Dental Materials Theory, Practice, and Cases (3rd Ed 2009)
The strength and other physical properties, EXCEPT wear resistance and surface roughness, of macrofilled composites are adequate for Class III, IV, and V restorations. Excessive wear when used for Class I and II restorations limited their posterior use. Macrofills were used before dentinal bonding systems were developed; placing them in posterior teeth resulted in postoperative sensitivity, leakage, and recurrent decay.
The problem with microfilled composites is the low percentage filler (40–50%). The surface area of the very small filler particles requires much more resin to wet the surface of the filler particles. This high resin content results in an increased coefficient of thermal expansion and lower strength.
Microfilled composites were used when esthetics are the dominant concern. Large composite restorations, such as an extensive Class IV restoration, are built in layers of several different shades and translucencies. The first layers to be placed are a hybrid composite selected for strength. The final layer, a veneer of sorts, is a microfilled composite selected for surface luster.
Microfilled composites are also used in Class V restorations at the cemento–enamel junction. Microfills have a lower modulus of elasticity and flex with the tooth better than the strongest composite materials. Clinical research has shown Class V microfill composite restorations are more likely to be retained than other composite materials.
Hybrid composites are very popular; their strength and abrasion resistance are acceptable for small to medium Class I and II restorations. Their surface finish is nearly as good as that of microfills; thus, they are also used for Class III and IV restorations.
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