Genotoxicity in gingival cells of patients undergoing tooth restoration with two different dental composite materials

Abstract

Dental composite materials come into direct contact with oral tissue, especially gingival cells. This study was performed to evaluate possible DNA damage to gingival cells exposed to resin composite dental materials. Class V restorations were placed in 30 adult patients using two different composite resins. The epithelial cells of the gingival area along the composite restoration were sampled prior to and after 7, 30, and 180days following the restoration of the tooth. DNA damage was analysed by comet and micronucleus assays in gingival exfoliated epithelial cells. The results showed significantly higher comet assay parameters (tail length and % DNA in the tail) within periods of 30 and 180days. The micronucleus test for the same exposure time demonstrated a higher number of cells with micronuclei, karyolysis, and nuclear buds. Results did not reveal any difference between the two composite materials for the same duration of exposure. Based on the results, we can conclude that the use of composite resins causes cellular damage. As dental composite resins remain in intimate contact with oral tissue over a long period of time, further research on their possible genotoxicity is advisable. Long-term exposure of gingival cells to two different composite materials demonstrated certain DNA damage. However, considering the significant decline in micronuclei frequency after 180days and efficiency in the repair of primary DNA damage, the observed effects could not be indicated as biologically relevant.