The peril of microplastics and nanoplastics on periodontal tissue

Periodontitis, a chronic inflammatory disease triggered by microbial dysbiosis and host immune dysregulation, is characterized by gingival inflammation, alveolar bone resorption, and eventual tooth loss, imposing a substantial burden on global oral health. In recent years, microplastics (MPs, 1μm–5 mm) and nanoplastics (NPs, 1nm–1 μm), as ubiquitous environmental pollutants, have emerged as novel risk factors for various systemic and local inflammatory disorders. However, the potential impact of MNPs on periodontitis remains incompletely investigated and poorly delineated. This review systematically synthesizes the current evidence regarding the association between MNPs and periodontitis, focusing on oral MNPs exposure routes, bioaccumulation characteristics in periodontal tissues, and the underlying pathogenic mechanisms. Oral MNPs exposure occurs through multiple pathways, including ingestion, inhalation and direct contact. These particles can accumulate in oral environment and interact with periodontal cells to elicit pathogenic responses. Mechanistically, MNPs may exacerbate periodontitis through interconnected pathways: cytotoxicity, oral microbiome homeostasis disruption, oxidative stress induction, chronic inflammation promotion, alveolar bone remodeling dysregulation and tissue repair capacity impairment. Elucidating of these mechanisms is crucial for developing targeted strategies to mitigate this escalating threat to both environmental and oral health.