Water Storage Effect on Mechanical Stability of Self-Adhesive/Universal Resin Cements

Objectives: Sufficient resistance to water degradation is a pre-requisite for the clinical success of resin-based dental materials. In this study the long-term stability in water of a self-adhesive and a universal resin cement containing hydrophilic adhesion monomers was determined by flexural strength testing.
Methods: 3-point flexural strength (n=6, in accordance with ISO 4049:2019) of 3M™ RelyX™ Unicem 2 Automix Self-Adhesive Resin Cement (RUN) and 3M™ RelyX™ Universal Resin Cement (RUV) was tested after 24 hours, 3-, 6- and 9-months storage in deionised water at 36°C. Both self-cure (sc) and light cure (lc) modes were investigated. For each cement, data was analysed by One-Way ANOVA separated for self-cure and light-cure mode (Tukey; p<0.05).
Results: No statistically significant change in flexural strength was observed for RUN (significance level α = 0,05; p-Value (sc)= 0,059; p-Value (lc)= 0,135) and RUV (significance level α = 0,05; p-Value (sc)= 0,225; p-Value (lc)= 0,584).
Conclusions: Cements investigated displayed high mechanical stability during water storage.