MORPHOLOGICAL STUDY OF CYTOTOXICITY OF LIGHTCURING NANOCOMPOSITE PARTICLES IN RAT MODEL

Abstract

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Aim. To study the cytotoxicity of glass-ionomer cement Vitremer (V), a nanocomposite for direct restorations of Filtek Ultimate (FU) and particles of the FU nanocomposite in an experiment on laboratory rats. Material and Methods. Experimental rats in the precervical area of the first maxillary molar were provided with a cavity in which V glass-ionomer fillings, a FU glass nanocomposite for direct restorations or daily powdered FU nanocomposite powder were placed in the cavity. On the 14th day, the animals were removed from the experiment. For morphological studies, a gum site was taken from the animals adjacent to the prepared cavity and a gum site from the opposite side of the dentition and paraffin sections were made. For histological examination, the dewaxed sections were stained with hematoxylin and eosin. Results and Discussion. For animals with fillings made of nanocomposite, as well as those which a powder was placed in the cavity of the tooth, significant changes in the structure of the gingival mucosa were revealed, the signs of hyperkeratosis and chronic inflammation are characteristic, and, in addition, the presence of cysts, both in the surface and basal layers of the epithelial layer. Conclusions. Taking into account the negative influence of the nanocomposite particles on the gingival mucosa, we consider it advisable to limit the use of the test material to occlusal surfaces.