Dental Calculus Microplastics: Exposure Assessment And Cytotoxicity On Gingival Fibroblasts

Given emerging evidence of MP accumulation in vital organs (e.g., heart, brain, bone marrow) and their documented health risks, yet oral cavity-specific exposure and cellular impacts remain uncharacterized, this study aims to investigate microplastic (MP) exposure levels in dental calculus and evaluate their potential effects on human gingival fibroblasts (HGF). The specific objectives of this project are i) characterizing alterations in the surface morphology, chemical composition and size distribution of MPs from human dental calculus by Laser Direct lnfrared lmaging (LDlR), ii) elucidating the toxic mechanisms of MPs exposure on human gingival fibroblasts through cytotoxicity tests, scratch assay, apoptosis assay, quantitative polymerase chainreaction (qPCR), and western blotting (WB) MPs were detected in all samples, with an average concentration of 3642 particles/g. Twenty-four types of microplastics wereidentified and the five most common detected polymer types are Polyamide (PA), polyethylene (PE), polyurethane(PU), fuororubber(FLU) and ethviene acrylic acid (EAA). Exposure of HGF to MP resulted in decreased cell viability, reduced migratory, andincreased apoptotic rate. Therefore, this study provides evidence that MP can reside persistently in the oral environment, posing potential risks to oral health