Mechanical reinforcement of glass ionomer cement using chitosan and fluoride-loaded nanochitosan: an in vitro comparative study

To evaluate the effect of chitosan and fluoride-loaded nanochitosan incorporation on the mechanical performance of a conventional glass ionomer cement (GIC). Fluoride-loaded chitosan nanoparticles were synthesized via ionic gelation and incorporated into the powder component of a conventional GIC (Fuji IX) at 10 wt%. A chitosan-modified GIC (CH-GIC) and an unmodified GIC served as comparison groups. Standardized specimens ( n = 10 per group) were prepared and stored at 37 °C for 24 h prior to testing. Compressive strength, flexural strength, and Vickers surface hardness were evaluated. Data were analyzed using one-way ANOVA and Tukey’s HSD test (α = 0.05). Both chitosan and nanochitosan incorporation significantly improved the mechanical properties of GIC ( p < 0.05). The nanochitosan-modified group (NCH-GIC) exhibited the highest compressive strength (184.27 ± 21.67 MPa), flexural strength (58.44 ± 7.82 MPa), and surface hardness (67.65 ± 7.82 VHN), followed by CH-GIC and conventional GIC. Modification of glass ionomer cement with fluoride-loaded nanochitosan significantly improved its compressive strength, flexural strength, and surface hardness after 24 h of storage. These findings demonstrate enhanced mechanical performance under the experimental conditions of the present study. However, further studies incorporating long-term aging protocols, fatigue testing, wear evaluation, and clinical validation are required to determine whether these improvements are maintained over time and translate into improved long-term clinical performance.