In Vitro Assessment of Corrosion Rate, Vickers Hardness and SEM Analysis of Glass Ionomer Cements and Calcium...

The long-term stability of bioactive dental cements in acidic environments is not yet fully understood, despite their extensive clinical use in restorative and endodontic procedures. The objective of this study is to evaluate the degradation behaviour and mechanical stability of one glass ionomer cement (GC FUJI IX^®) and two calcium-silicate-based materials (Biodentine^® and Biodentine XP 500^®) under simulated acidic oral conditions. A total of 18 samples were prepared and distributed into three groups. The materials were immersed in a solution with a pH of 4.5, and their performance was assessed through a number of different methods. These included mass-loss measurements, corrosion-rate calculations, Vickers microhardness testing, and SEM to characterise the surfaces. Biodentine^® exhibited the highest degradation, followed by Bio-Dentine XP 500^® and GC FUJI IX^®. The data were confirmed by one-way ANOVA and a post hoc Tukey's test. This indicated a statistically significant superiority (p < 0.05) of Biodentine XP 500^® over glass ionomers in terms of surface hardness maintenance under acidic conditions. Biodentine^®, a calcium silicate-based material, demonstrated inferior chemical stability compared to GC FUJI IX^® and Biodentine XP 500^®, likely due to its modified calcium-silicate formulation that limits ionic dissolution. In addition, the study revealed that Biodentine XP 500^® exhibited the highest Vickers hardness under acidic conditions. The findings reported in this study offer valuable insights into the material selection process for low-pH clinical scenarios and contribute to a more comprehensive understanding of the chemical-mechanical stability of modern bioactive dental restoratives.