In vitro comparison of pH, solubility, and radiopacity of two dual-cure resin cements

Background: Understanding the properties of dual-cure resin cements is essential for ensuring clinical success. The present study compared the pH, solubility, and radiopacity of the dual-cure resin cements NX3 Nexus^® and Variolink N^®. Methods: This in vitro experimental study prepared 30 standardized dual-cure resin cement discs (8 mm diameter × 1 mm thickness). Discs were equally allocated to two groups (n = 15) —NX3 Nexus^® and Variolink N^®— and, within each cement, randomly assigned to three subgroups for pH, solubility, and radiopacity testing (n = 5 per subgroup). The non-parametric Mann–Whitney U test was employed for comparisons of solubility and pH, while the parametric Student’s t-test was employed for radiopacity. A significance level of p < 0.05 was considered. Results: Significant differences were observed between NX3 Nexus and Variolink N when comparing pH (p = 0.008) and radiopacity (p = 0.026). Both resin cements showed no differences when comparing solubility (p = 0.841). Conclusion: Under the present in vitro conditions, NX3 Nexus^® and Variolink N^® demonstrated low solubility and comparable pH. Variolink N^®’s higher radiopacity may aid radiographic detection of excess cement and marginal assessment; thus, it may be preferred when radiographic evaluation is critical, whereas either cement is appropriate otherwise.