Mechanical Properties of Glass Ionomer Cements

Glass ionomer cements (GICs) are water-based, acid–base composites formed by the reaction of a fluoroaluminosilicate glass powder and an aqueous polyacid. Their attraction in restorative and luting applications stems from simultaneous adhesion to tooth substrates, sustained fluoride release and intrinsic bioactivity, notably the gradual development of a durable ion-exchange interfacial layer. Despite these favourable features, conventional GICs suffer from limited mechanical performance: relatively low compressive and flexural strength, brittleness and modest fracture toughness restrict their use in high-loading regions. Resin-modified variants (RMGICs) introduce polymerisable monomers to improve early strength and handling but may compromise biocompatibility and long-term stability. Contemporary research seeks to enhance mechanical resilience through nanoparticulate fillers, bioactive glass incorporation, polymer functionalisation and natural-biopolymer reinforcement. By tailoring microstructure—reducing porosity, promoting controlled ion diffusion and refining interfacial cohesion—these strategies aim to extend the clinical scope of GICs towards load-bearing restorations, atraumatic treatment techniques and durable adhesive applications in both high- and low-resource settings.

Research from Nature Portfolio

Recent studies have employed in situ non-destructive spectroscopic methods to uncover the atomic and vibrational origins of toughness development during cement setting. Through calorimetry, terahertz spectroscopy and neutron scattering, it was shown that fracture toughness evolves non-monotonically, with identifiable coupling points between glass and polymer phases. Key findings include an early setting recovery in toughness, stress-induced interfacial weakening and a subsequent asymptotic decline towards long-term values. This atomic-scale insight into interfacial dynamics offers a framework for engineering the setting process to achieve higher toughness and resilience in bioactive cements.

Mechanical Properties of Glass Ionomer Cements publication trend

The graph below shows the total number of articles in mechanical properties of glass ionomer cements across all publications each year (not limited to Nature Index journals).

Technical terms

Glass ionomer cement (GIC): A water-based acid–base restorative material formed by reaction of fluoroaluminosilicate glass and polyacrylic acid.

Resin-modified glass ionomer cement (RMGIC): A GIC variant containing polymerisable monomers to improve early mechanical strength and handling.

Compressive strength: The maximum axial load a material can withstand before failure under crushing forces.

Flexural strength: The stress at which a material fails in bending, reflecting its resistance to deformation under load.

Fracture toughness: A measure of a material’s ability to resist crack propagation under stress.

Elastic modulus: The ratio of stress to strain in the elastic deformation region, indicating stiffness.

Bioactive glass nanoparticles: Nano-sized glass fillers that release therapeutic ions and contribute to secondary mineralisation.

Ion-exchange layer: A chemically bonded interfacial zone formed at the GIC–tooth boundary, enhancing adhesion and durability.

References

1. Assessment of Mechanical/Chemical Properties and Cytotoxicity of Resin-Modified Glass Ionomer Cements Containing Sr/F-Bioactive Glass Nanoparticles and Methacrylate Functionalized Polyacids. International Journal of Molecular Sciences (2023).
2. Oxidized Natural Biopolymer for Enhanced Surface, Physical and Mechanical Properties of Glass Ionomer Luting Cement. Polymers (2023).
3. Atomic and vibrational origins of mechanical toughness in bioactive cement during setting. Nature Communications (2015).