Effects of Composite Thickness on the Shear Bond Strength to Dentin

The manufacturers of some condensable posterior composites claim that their products can be placed in bulk and light-cured in 5-mm-thick increments. This study compared the shear bond strengths of three composite resins when bonded to dentin in 2- and 5-mm-thick increments. Overall the bond strengths were adversely affected by the composite thickness (p 0.0001). The shear bond strength of each composite tested was much lower when polymerized in a 5-mm increment than in a 2-mm increment of composite (p 0.0005). The two condensable composites tested had a lower bond strength than the conventional composite when polymerized in a 5-mm bulk increment (p 0.01).

MeSH Key Words: composite resins; dental bonding; dentin-bonding systems