Microleakage Evaluation of Expired and Non-expired Resin Composites and Bonding Agents: In Vitro Study

Abstract

Aim: Although the shelf life is a key property of dental composites and bonding agents, these materials may often be used in simple procedures after expiration. In this study, the microleakage of two year expired and non-expired dental composites (Filtek Ultimate Universal A2 Enamel, 3M ESPE, USA, and Tetric N Ceram A2, Ivoclar Vivadent, Schaan, Liechtenstein) and a universal bonding system (Single Bond Universal, 3M ESPE, USA) was examined. Materials and Methods: In 40 freshly extracted human molars, two standardized Class II cavities (buccolingual and mesiodistal width of 3 mm and 4 mm, respectively) were prepared (80 cavity preparations). The teeth were thermocycled in distilled water for 1000 cycles in a 5°C to 55°C water bath. Next, the teeth and their apical foramens were coated with water resistant nail varnish, except for 1 mm around the restoration–tooth interface, and retained in a 1% methylene blue solution. After 24 h, the specimens were cut into two halves and analyzed using a stereomicroscope. Scanning electron microscopy images of two samples of the groups were obtained. Results: The Kruskal–Wallis test indicated no significant differences between the groups ( P < .05). The occlusal median scores were not significant ( P = .99). Moreover, the gingival median scores were not significant ( P = .48). No difference was found between the occlusal and gingival values in any group ( P > .05). Conclusion: These findings indicated that two-year-expired dental composites and bonding agent, which were maintained under proper conditions, do not have any significant difference in terms of the microleakage.

Adhesion and Surface Roughness of Apatite-Containing Carbomer and Improved Ionically Bioactive Resin Compared to Glass Ionomers

“…However, a durable bond must be established between all materials to succeed in this application. In other words, the base material's bond strength must be as strong with the resin composite as it is with the dental tissues [25]. Koç Vural et al [24] showed that using a base material under different resin composites significantly reduced polymerization shrinkage.…”