Cytotoxicity of Zirconium Oxide Nanoparticles on Rabbit Tooth Gum Cells

The cytotoxicity mechanism of zirconium oxide nanoparticles (ZrO 2 -NPs) has not been clarified to-date. Nevertheless, the generation of reactive oxygen species (ROS) by ZrO 2 -NPs has been perceived as an important mechanism in some in vivo studies. Accordingly, this study was conducted to identify the potential effects of ZrO 2 -NPs on rabbit tooth gum cells as well as the mechanism/s of their cytotoxicity. Synthesized ZrO 2 -NPs were characterized using scanning electron microscopy (SEM), dynamic light scattering (DLS), Cell viability, ROS level, lipid peroxidation (LPO), mitochondrial membrane potential (MMP), glutathione count (GSH/GSSG), lysosome damage and apoptosis/necrosis were evaluated. Biodistribution studies were conducted on tooth gum, liver, kidney, heart and brain tissues in the rabbit using inductively coupled plasma optical emission spectrometry (ICP/OES). ZrO 2 -NPs increased ROS, MMP collapse and malondialdehyde (MDA). In contrast, GSH/GSSG and apoptosis/necrosis were found to be changed. The ZrO 2 -NPs accumulated significantly more on rabbit tooth gum tissues compared with other organs ([Formula: see text]). The study provided evidence that ZrO 2 -NPs cannot be considered completely biocompatible in the gum cell tissues of the rabbit. Before these nanoparticles can be used for human dental applications, further investigations on a wide range of cell death signaling should be performed.