Durability of four composite resin cements bonded to dentin under simulated pulpal pressure

ObjectivesThis study aimed to investigate the durability of four adhesive luting systems bonded to dentin with and without simulated hydrostatic pulpal pressure (PP).MethodsComposite blocks were bonded to dentin with four adhesive systems: Multilink Automix (MA), Multilink Sprint (MS), Clearfil Esthetic cement (CE) and RelyX ARC (RAC) under either a PP of 0 or 15 cm H2O. After 3 d water storage at 37 °C or thermal cycling (TC), of 30 d with 5000 TC or 90 d with 15,000 TC micro-tensile bond strength (μTBS) was tested. Failure analysis of the bonding interface was performed using a scanning electron microscope (SEM).ResultsIndependent of PP application groups MA and RAC showed significantly higher μTBS than CE and MS (P ≤ 0.05). A significant decrease in μTBS was found for RAC and MS when subjected to PP (P ≤ 0.05), whereas CE and MA showed no significant difference (P > 0.05). TC had no significant influence on the μTBS in RAC, MA and CE without PP application (P > 0.05), whereas CE with PP and MS showed a significant decrease in μTBS (P ≤ 0.05) when subjected to TC.SignificanceBased on these results, there were significant differences between materials. Pulpal pressure and artificial aging also seem to have an effect on in-vitro evaluation of bonding durability. If considered relevant to the materials’ service performance then these conditions should be applied in the materials’ testing.