Mechanoluminescent Resin Composites: Fabrication, Characterization, And Dual-Function Applications

This study developed mechanoluminescent resin composites for oral applications, focusing on their microstructure, stress-responsive optical properties. The research targeted dual functionalities: visualizing occlusal forces to detect interference and enhancing resin curing depth through mechanoluminescence-assisted photopolymerization. Mechanoluminescent nanoparticles were synthesized via sol-gel processing and embedded into a light-curable resin matrix. Structural characterization employed XRD, SEM, and TEM to evaluate crystallinity and dispersion. FTIR and TGA assessed chemical interactions and thermal stability. A custom ML testing system quantified stress-luminescence correlations, while cyclic loading and simulated oral environments evaluated mechanical resilience and service stability. Biocompatibility was verified through MTT cytotoxicity assays with oral fibroblasts. The composites demonstrated homogeneous nanoparticle distribution with stable resin-nanoparticle interfaces. Stress-dependent luminescence showed linear intensity-stress correlation (R² > 0.95), achieving detectable emission at 1.5 MPa through optimized doping. Cyclic tests revealed <5% intensity loss after 10³ loading cycles, confirming fatigue resistance. Environmental aging induced only 12% luminescence decay over 30 days, while cytotoxicity assays showed >90% cell viability, meeting ISO standards. The blue emission (450 nm) increased resin curing depth by 38% compared to conventional light-curing. The mechanoluminescent composites exhibit dual clinical potentials: 1) As a dynamic occlusal sensor enabling real-time force mapping, surpassing static detection methods; 2) As an auto-photopolymerization enhancer improving restoration durability. Their stress-responsive functionality, environmental stability, and biocompatibility position them as innovative smart materials for preventive dentistry and restorative optimization. Future work will focus on wavelength tuning and clinical protocol development.