Neurotoxicity and mechanism of dental nanomaterials

Recently, the dental application of nano materials has made progress in clinical treatment, such as implant surface modification as well as antibacterial, and controlled release. However, the active physical and chemical properties of nanomaterials may pose a potential safety risk in humans. Dental nanomaterials used for oral application can be released into the blood through a variety of mechanisms, and they can penetrate the blood-brain barrier and enter the central nervous system. Moreover, nanomaterials can also directly affect the central nervous system through the olfactory nerve and via sensory nerve terminal transport, causing organic and functional damage to central nerves, and even causing neurotoxicity during embryo development. Nanomaterials can interact with biomolecules such as cells, genes, and proteins in the body, and can produce neurotoxicity through the mechanisms of inducing oxidative stress, inflammatory responses, cell autophagy, apoptosis, genotoxicity, etc. Factors affecting the toxicity of nanomaterials include particle size, concentration, and solubility. Dental nanomaterials and their pathways into the central nervous system, as well as the mechanisms that may cause neurotoxicity, will be discussed on this review.