A comparative study of shear bond strength of two adhesive liners to nanocomposite

Abstract

Aim: To compare the shear bond strength of resin-modified glass ionomer and nano-filled flowable composite liners to nanocomposite restorative material. Materials and Methods: In this in vitro study, 24 specimens were prepared in acrylic blocks for the study with 12 in each group. Group I consisted of resin-modified glass ionomer liner (GC Fuji II LC Improved) bonded to a cylinder of nanocomposite (Z350 Universal Restorative) whereas in Group II flowable composite liner (Filtek Z350 Flowable Restorative) was bonded to a cylinder of nanocomposite (Z350 Universal Restorative). Shear bond strength was determined using Instron Universal testing machine. Student's independent sample t test was used for analysis. Results: The mean shear bond strength value of Group I was greater than Group II and the difference was statistically significant (P = 0.001). Conclusion: Resin-modified glass ionomer appears to be a more compatible liner under nanocomposite restoration than flowable composite as it exhibited significantly higher shear bond strength.Clinical Relevance to Interdisciplinary DentistryResin-modified glass ionomer and flowable composites have been used as liners under resin composite restorations in both primary and permanent teeth to compensate for their polymerization shrinkage.Adequate bonding of liners to composites is as important as bonding to dentin for the success of this technique.Bonding of resin-modified glass ionomer liner to nanocomposite restorative material is better than flowable composite liner and hence should be preferred over flowable composite as a liner.