Hybrid layer evaluation of all-in-one adhesive with single and multiple applications

Background: Earliest commercial versions of self-etch bonding systems were hydrophobic, which did not allow them to adapt to hydrophilic dentin. The adhesive must be hydrophilic in nature as it should be able to diffuse and penetrate in an aqueous environment. The tested self-etching adhesive (Tetric N-bond) contains acid monomers, often mixed with water, to make the adhesive systems sufficiently acidic to form hybridized complex. Single layer application of self-etch adhesive results in a layer that is too thin for successful photopolymerization. Aim: The purpose of this study was to evaluate the effect of single and multiple applications of all-in-one self-etch adhesive on hybrid layer. Materials and Methods: Tetric N-Bond self-etch all-in-one adhesive was used in the study. Fifteen extracted human mandibular molars mounted in self-cure acrylic resin with the occlusal enamel removed were cross-sectioned to obtain 1 mm thick dentin disks and then divided into three groups.• Group 1: Single layer of adhesive was applied and light cured for 10 s;• Group 2: Two layers of adhesive were applied with intermediate curing between each layer;• Group 3: Two consecutive layers of adhesive were applied with light curing after application of two layers. Resin composite build-ups were made and hybrid layer evaluation was done using scanning electron microscope.Results: There is no significant relationship between increase in number of adhesive layers and thickness of hybrid layer. There is no significant relationship between curing each layer and curing of two consecutive layers of adhesive. Conclusion: No significant relationship exists between increase in number of adhesive layers and thickness of hybrid layer. Clinical significance: Self-etching adhesive systems allow practitioner to place restorations in a more simplified manner with decreased postoperative sensitivity. After application, these products create very thin coatings, which may be oxygen inhibited and hence poorly polymerized which can be overcome by ...