Xylotrupes gideon microchitosan-modified glass ionomer cement: in vitro assessment of mechanical properties

Background: Glass ionomer cements (GIC) are valued as inherent fluoride-releasing dental restorative materials, while chitosan binds to negatively charged enamel surfaces, promoting mineral deposition and strengthening teeth. This study aimed to evaluate the mechanical properties of GIC modified with microchitosan derived from Xylotrupes gideon, using an in vitro experimental design. This study uniquely employs micro-scaled chitosan derived from the exoskeleton of Xylotrupes gideon, an insect-based, locally sourced, and environmentally sustainable alternative to conventional marine chitosan, to reinforce a conventional GIC. Materials and methods: Microchitosan was extracted from Xylotrupes gideon and incorporated into conventional GIC at 0.5%, 1% and 2% (w/w). Compressive strength, diametral tensile strength, and surface microhardness were measured using standard testing equipment after immersion in artificial saliva for 24 h and 7 days. Statistical analysis was performed using one-way ANOVA followed by the Games-Howell post hoc test, with significance set at p < 0.05. Results: The 1% microchitosan-modified GIC exhibited the most significant improvements compared to the unmodified control. After 7 days, compressive strength increased by 35.4%, diametral tensile strength by 51.3%, and surface hardness by 46.6% (p < 0.05). These enhancements are attributed to microscale reinforcement and chemical bonding between microchitosan and the GIC matrix. Conclusion: The addition of 1% microchitosan derived from Xylotrupes gideon significantly improved the mechanical performance of GIC. This bioactive reinforcement shows promising potential for clinical restorative applications, though further investigation into its long-term biocompatibility and fluoride release is warranted. These findings highlight a novel combination of insect-derived micro-scale chitosan and conventional GIC, yielding mechanical gains comparable to those reported for nanochitosan-modified formulations while relying on a more sustainable chitosan source.