Microtensile bond strength of high-viscosity glass ionomer cements and nanoceramic composite to normal and caries-affected dentin: An in vitro study.

BACKGROUND

Modern caries management involves the removal of the carious dentin after selective removal of soft dentin while retaining the firm dentin and restoring with an appropriate restorative.

AIM: To evaluate and compare the microtensile bond strength (μTBS) of high-viscosity GC Glass Hybrid and Glass Ionomer FX Ultra cements with Ceram.x nanoceramic composite on normal dentin (ND) and artificially induced caries-affected dentin.

MATERIALS AND

METHODS

After collecting 90 extracted human mandibular molar teeth, the occlusal enamel was removed. Vestibulolingually teeth were sectioned into two halves, in which the distal half samples (n = 90) were subjected to pH cycling. Both mesial ND and distal artificial carious dentin (ACD) tooth halves were assigned to three groups (n = 15 each) depending on the restorative material tested. After undergoing thermomechanical cycling, dentin-restorative beams were subjected to μTBS testing, and the fracture type was analyzed under a scanning electron microscope. The bond strength data were assessed with one-way ANOVA and Tukey's multiple post hoc test by establishing α =0.05 significance.

RESULTS

The mean μTBS of Ceram.x composite for both ND and ACD was significantly higher when compared to both high-viscosity glass ionomer cements (GICs) examined (P = 0.0001). The μTBS of GC Hybrid and FX Ultra Tested were not different from each other in both the substrates (P = 0.6518 in ND and P = 0.9603 in ACD). Nanocomposite exhibited more adhesive failures, whereas the tested GICs showed a cohesive mode of failures.

CONCLUSION

Caries-simulated dentin has substantially lower μTBS values than ND. The μTBS values of the two tested GICs were much lower than the mean bond strength of the nanocomposite.