Implications of Graphene-Based Materials in Dentistry

Objectives: The integration of graphene into root canal sealers (RCS) might improve their mechanical properties and biocompatibility. Herein, we investigate the impact of graphene incorporation on AH Plus epoxy resin root canal sealer (RCS), examining its mechanical and biological properties across various concentrations.
Methods: Cylindrical specimens (3 mm × 3.58 mm, n= 60) of graphene-modified RCS at 0.1%, 0.5%, and 1.0% w/w concentrations and a control group of unmodified epoxy resin RCS were fabricated, then conditioned at 37°C and 95% relative humidity for 6 hours. Rheological properties were assessed using a Kinexus Ultra rheometer (1 Hz, 1% strain). Compressive strength was evaluated using an Instron 3345 testing machine. Morphology was analyzed with scanning electron microscopy (SEM). Biocompatibility assessment was conducted using BALB3T3 fibroblasts through resazurin-based metabolic activity assays. Cells were cultured in complete DMEM supplemented with 10% FBS and 1% penicillin/streptomycin. Cell viability was evaluated at 24 and 48 hours, using fluorescence measurements (λex = 560 nm, λem = 590 nm). Statistical significance was determined through two-way ANOVA, with Tukey's post-hoc test (p < 0.05).
Results: SEM analysis confirmed the successful integration of graphene within the RCS. However, graphene did not significantly enhance the compressive strength compared to the control. Furthermore, all modified formulations showed a significant decrease in storage moduli (p < 0.05). While biocompatibility assessment demonstrated that graphene modified specimens were biocompatible towards BALB 3T3 fibroblast cultures, cell viability studies showed no statistically significant enhancement after 48h.
Conclusions: Although all tested graphene concentrations maintained good biocompatibility towards BALB3T3, there was no enhancement in compressive strength across all tested groups. The observed reduction in storage moduli suggests that current integration methods may introduce structural defects in the hybrid material. These findings highlight the need for refined incorporation techniques and further exploration into optimal graphene concentrations.