From Oral Cavity to Whole Body: A Review of the Local and Systemic Toxicity Mechanisms and Health Risks of MNPs

Research on micro/nanoplastics (MNPs) focuses largely on systemic toxicity from gastrointestinal or respiratory exposure, overlooking the oral cavity as a critical first contact point. This gap obscures understanding of early exposure pathways and initial local effects.

This review systematically establishes the oral cavity as an "initial target organ." It synthesizes evidence on oral MNP exposure routes, their unique accumulation in biofilms and dental calculus, and mechanisms like physical abrasion, microbial dysbiosis, and the "Trojan horse" effect to construct an oral-specific toxicity framework.

Integrating advanced detection methods with models like PBTK reveals the oral cavity not as a passive conduit, but as an active "first amplifier" of MNP risk. The analysis details how MNPs initially interact with oral biological barriers.

The study positions the oral cavity as the origin of systemic MNP health risks, demonstrates the long-term implications of oral MNP accumulation, and provides a scientific foundation for advancing the field of environmental oral health.