Assessing the solubility of three resin-based luting cements in artificial saliva

The present study aimed to assess and compare the solubility of three resin-based luting cements in artificial saliva under varying pH conditions.

This in-vitro experimental study was conducted at the College of Dentistry, King Faisal University, Al Ahsa, Saudi Arabia, over a period of two months. A total of 45 disc-shaped specimens (8mm diameter, 4mm thickness) were prepared using cylindrical molds: 15 each of Self-Adhesive Methacrylate-Based Resin Cement (Non-MDP), Self-Adhesive MDP-Based Resin Cement, and Resin-Modified Glass Ionomer Cement. The specimens were light-cured for 40 seconds using an LED curing unit (450 mW/cm²) and finished with Sof-Lex discs. Each group was further subdivided, with five specimens immersed in artificial saliva at pH 3.4, pH 6.7, and distilled water at pH 7.0, respectively, for four weeks. Solubility was determined by calculating the mass loss of each specimen after immersion in the test solutions for four weeks. One-way ANOVA and Tukey's HSD post-hoc test were applied for group comparisons at a significance level of p < 0.05.

The solubility of all three cements was significantly higher in acidic artificial saliva (pH 3.4), with Self-Adhesive MDP-Based Resin Cement demonstrating the lowest solubility (0.022 ± 0.010 mg/mm³), and both Self-Adhesive Methacrylate-Based Resin Cement (Non-MDP) and RMGIC showing similarly high solubility values (0.08 ± 0.021 mg/mm³ and 0.08 ± 0.005 mg/mm³, respectively). No significant difference was observed among the groups at pH 6.7 and pH 7.0.

The solubility of resin-based luting cements is influenced by pH, with significantly greater degradation under acidic conditions. Self-Adhesive MDP-Based Resin Cement exhibited superior resistance, making it more suitable for low pH environments.