Bonding performance of different types of expired and unexpired composite resin cements

Aim: The aim of this study was to compare the bond strength of three expired and unexpired composite resin cements used between tooth and ceramic surfaces. Methodology: In this study, the dentin surfaces of 60 non-carious human teeth and ceramic specimens were bonded with three different resin cements. The resin cements used to bond the teeth and ceramic blocks were divided into two subgroups by expiration date (Group 1a. Variolink II-unexpired, 1b. Variolink II-expired 12 months prior. Group 2a. RelyX Unicem-unexpired, 2b. RelyX Unicem-expired 12 months prior. Group 3a. Panavia F 2.0-unexpired, 3b. Panavia F 2.0-expired 12 months prior). The samples were thermally cycled for 3,000 cycles in a temperature range of 5°C–55°C. The shear bonding test was performed using a universal tester. The force required for ceramic debonding was recorded. Surface fracture analysis was performed using a stereomicroscope. Mann–Whitney U test was used to compare the bond strength of resin cements with different expiration dates. P-value < 0.05 was considered statistically significant. Results: The difference in bond strength between the unexpired resin and the resin that had expired 12 months before the analysis was found not to be statistically significant in the Variolink II and Panavia pairs but significant in the RelyX resin cement pair. Conclusion: The self-adhesive resin cements that expired one year earlier showed lower bond strength than their unexpired counterparts; however, the use of expired total-etch and self-etch systems did not significantly affect bond strength. How to cite this article: Karagözoğlu İ, Aksel L. Bonding performance of different types of expired and unexpired composite resin cements. Int Dent Res 2023;13(2):54-59. https://doi.org/10.5577/idr.2023.vol13.no2.2 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.