Experimental and Computational Evaluation of Alloy-Reinforced Glass Ionomer Cement: Erosion Resistance, Maturation Behavior, and Predictive Modeling

Abstract

Glass ionomer cements (GICs) are widely used restorative materials due to their chemical adhesion, fluoride release, and biocompatibility. However, their susceptibility to acid erosion—particularly during early maturation—remains a significant limitation affecting long-term clinical performance. Recent developments in reinforced GIC formulations aim to improve resistance to mechanical and chemical degradation, yet their behavior under dynamic erosive conditions requires further investigation. This study aimed to evaluate the erosion resistance of an experimental high powder-to-liquid ratio glass ionomer cement (EXPT) in comparison with a metal-reinforced glass ionomer cement (Hi-Dense), and to investigate the influence of maturation time on material performance using both experimental and computational approaches. Cylindrical specimens (4 mm diameter; n = 6 per group) were prepared and tested at three time intervals: 1 hour, 24 hours, and 6 months. Erosion resistance was assessed using a standardized lactic acid jet test (0.02 M, pH 2.7) under controlled temperature (37°C) and flow conditions (120 ± 4 ml/min) for 24 hours. Erosion rates were quantified using both weight loss (mg/h) and dimensional loss (µm/h). Statistical analysis was performed using the Mann–Whitney U test (α = 0.05). In parallel, computational simulations incorporating diffusion–reaction modeling and finite element analysis (FEM) were conducted to predict ion transport, stress distribution, and degradation behavior. At early maturation stages, EXPT exhibited significantly higher erosion rates compared to Hi-Dense (p ≤ 0.005). Mean height loss at 1 hour was 8.7 ± 1.0 µm/h for EXPT and 2.9 ± 0.3 µm/h for Hi-Dense, while corresponding weight loss values were 0.30 ± 0.04 mg/h and 0.16 ± 0.02 mg/h, respectively. A significant reduction in erosion rates was observed for both materials with increasing maturation time. After 6 months, no statistically significant differences were detected between the two materials (p > 0.05). Computational simulations demonstrated strong agreement with experimental data (correlation coefficient r ≈ 0.9), predicting higher initial diffusion rates and localized stress concentrations in EXPT, and more uniform stress distribution in Hi-Dense. The enhanced performance of Hi-Dense cement is attributed to alloy reinforcement, which improves stress redistribution and reduces crack initiation under erosive conditions. The convergence of erosion rates over time highlights the dominant role of matrix maturation, characterized by increased crosslink density and reduced ion mobility. The combined experimental–computational approach provides mechanistic insight into erosion processes and validates the predictive capability of simulation models. Metal-reinforced glass ionomer cement demonstrates superior early-stage erosion resistance compared to conventional formulations, while long-term performance is largely governed by maturation processes. The integration of experimental testing with computational modeling offers a robust framework for evaluating and optimizing dental materials, with potential implications for improving clinical durability and guiding future material development.