Change of Cytotoxicity Level by the Addition of Nanomaterials

Abstract

The development of nanomaterials has promoted a marked improvement of performance and studies on the addition of new functions. Nanomaterials may be combined in many dental component materials in the future. However, at present, the results of studies on the biological safety of nanomaterials are insufficient. Cells have an active nanomaterial uptake mechanism, i.e., phagocytosis, and this is completely different from the mechanism of incorporating dissolved chemical substances. Moreover, products prepared with nanomaterials alone are rarely developed, and nanomaterials are likely to be added to conventional chemical substances. In this case, there are no data on changes in the toxicity caused by interaction between nanomaterials and dissolved chemical substances. Thus, we investigated the cytotoxicity of nano-zinc oxide alone and changes in the cytotoxicity of Bis-GMA, which is used as a matrix resin monomer of composite resin, at its non-cytotoxic concentration. Bis-GMA cytotoxicity increased in the nano-zinc oxide group compared with that in the control group in both 2- and 3-dimensional culture using collagen gel. It was clarified that the cytotoxicity of Bis-GMA slightly increased due to interaction in the nano-zinc oxide and Bis-GMA mixture.