Evaluation of gap formation at the composite resin‐tooth interface after using universal adhesives: In vitro SEM study using the replica technique

Abstract

The aim of this study was to evaluate gap formation after using two universal adhesives, Peak Universal Bond (P), which contains chlorhexidine and Adhese Universal (A), which contains 10‐MDP monomer, and to compare them with two gold standard adhesives. The adhesives were tested in different etching modes, etch‐and‐rinse (ER) or self‐etch (SE), and under thermomechanical loading (TML). Two identical Class V cavities were prepared in each of 30 human third molar teeth, and resin‐composite restorations were made. Before and after TML, replicas of the restorations were prepared. Gap formation and their frequency according to the modified classification of Blunck and Zaslansky and the width of the maximum marginal gap (MG) were separately evaluated in enamel and dentin. Gap frequency did not differ significantly only in the enamel before TML, despite the use of different adhesives or etching modes. At both timepoints, the highest MG values were obtained with the Peak Universal Bond self‐etch (PSE) group in enamel (6.2 μm before TML, 12.2 μm after TML) and the Peak Universal Bond etch‐and‐rinse (PER) group in dentine (21.3 μm before TML, 35.5 μm after TML). After TML, there was a significant increase of gap frequency for Adhese universal self‐etch (ASE) group and MG values for PER, PSE, ASE groups at the resin‐enamel interface, and gap frequency and MG values for all groups at the resin‐dentin interface. Universal adhesive with 10‐MDP monomer have beneficial effect on the resin‐dentin interface, while chlorhexidine may reduce the resistance of the universal adhesive system to oral cavity conditions.

The Cytotoxicity and Genotoxicity of Three Dental Universal Adhesives—An In Vitro Study

“…Manufacturers still change the composition and properties of dental adhesives to increase the longevity of restoration. The major factors affecting the bonding durability of dental adhesives include not only the type of solvent, the chemical components, their molecular weights or the pH associated with proper preparation of the tooth surface, but also additional components, added to improve bonding durability, including collagen crosslinking agents, antioxidants and protease inhibitors [10].…”

The influence of a composite resin adhesive on microleakage into the implant screw access chamber

“…The selected scanning resolution of five microns was many times larger than the size of ferrous sulphate ions and thus the scanner’s sensitivity relied on a minimum aggregation for detection. By comparison, the marginal discrepancies between composite resin restorations and natural teeth range from 0.5 µm to more than 100 µm 27–30 . It was therefore proposed our described experimental parameters were appropriate for a study of this kind.…”

Monowave and polywave light-curing of bulk-fill resin composites: degree of conversion and marginal adaptation following thermomechanical aging

“…The formation of marginal gaps in RCs restoration is very complex. It involves several factors, such as interface stress during light-curing [7], quality of bonding [31], linear coefficient of thermal expansion [32], mastication loading over the restoration [33] and the quality of cure [9].…”