Microtensile Bond Strength of Fiber Reinforced and Particulate Filler Composite to Coronal and Pulp Chamber Floor Denin

The objective of this in vitro study was to compare microtensile bond strength of fiber reinforced composite and particulate filler composite to coronal and pulp chamber floor dentin using self- etching adhesive system. Forty human molar teeth, were divided into two experimental groups (n = 20 per group). In the first group, coronal dentin was exposed by cutting of occlusal enamel with the Isomet saw. In the second group, pulp chamber floor dentin was exposed by trepanation, after which chemo- mechanical instrumentation and root canal filling were performed. These two groups were further subdivided into two groups (n=10) according to the type of composite: fiber reinforced composite (everX Posterior, GC, Tokyo, Japan, ) and particulate filler composite (G- aenial Posterior, GC, Tokyo, Japan). A self-etching adhesive system (G-aenial Bond, GC, Tokyo, Japan) was used for all specimens. In the group with exposed coronal dentin, 5 mm high composite blocks were built up with each of the tested composites. In the group with exposed pulp chamber floor dentin, composite resin blocks were built to the level of occlusal surface. Each specimen was serially sectioned to obtain sticks with a cross- sectional area of 1 mm2, and microtensile bond strength test was performed (Figure 1). Statistical analysis was performed using one-way ANOVA test at level of significance set at 5%. Microtensile bond strength values were significantly higher for coronal dentin in comparison to pulp chamber floor dentin (p0.05), (Figure 2). Only the adhesive type of failure was observed in all four experimental groups. Higher microtensile bond strength values were observed for coronal dentin than for pulp chamber floor dentin. Fiber reinforeced and particulate filler composite performed similarly regarding the microtensile bond strength.