159 - Evaluation of Microplastics Generation During Simulated Toothbrushing

Abstract:

Purpose: Microplastics, increasingly recognized for their environmental persistence and potential health implications, are of particular concern in the pediatric population due to heightened susceptibility to endocrine-disrupting chemicals. Routine toothbrushing has been identified as a source of microplastics generation. Our work aims to quantify microplastic generation during simulated toothbrushing and evaluate the influence of toothbrush material and bristle hardness on particle release.

Methods: The substrates selected for this study consisted of ex vivo, non-carious human molars. Three brands of brush each in a firmer and softer bristle weight were subjected to a standard 1-year brushing simulation cycle on a mechanical brushing simulator. After completing the cycle, tooth and brush were each thoroughly rinsed to collect particulate matter for analysis. Following ultracentrifugation, resulting brushing effluent solids were analyzed via SEM (Scanning Electron Microscopy), NMR (Nuclear Magnetic Resonance), and FTIR (Fourier Transform Infrared Spectroscopy) to evaluate the structure and composition of the solid material.

Conclusion: Current efforts have resulted in standardized procedures for evaluating different toothbrush bristle materials, determining the number of biological and technical replicates needed to form conclusions regarding the impact of bristle type. Preliminary results show the impact of simulated brushing is more pronounced on soft bristle brushing, where the breakdown of the bristle is observed through the fraying of the Nylon. Moving forward, we aim to apply this protocol to various toothbrush models, evaluating the differences between brands, bristle type, and the intended consumer to inform safer oral hygiene product design

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