In vitro evulation of the effects of N-acetylcystei̇n addition on various biocompability parameters of some composites in gingival color

In-Vitro Evaluation of the Effects of N-Acetylcystein Addition On Various Biocompatibility Parameters of Some Composites in Gingival Color Objective: The aim of this study was to investigate the cytotoxic and apoptotic effects of the composites which are used in esthetic restorative therapies of gingival recessions and servical tooth defects by cell culture technique and to analyze the potential biological impacts of Nacetylcysteine that is added to these materials. Method: In our study, two different gingival composites (PermaFlo Pink Ultradent, South Jordan, USA) (Amaris Gingiva, VOCO, Cuxhaven, Germany) and one traditional flowable composite (Filtek Ultimate Flowable, 3M ESPE, Seefeld, Germany) were used. Six samples of 5 mm diameter and 2 mm thickness were prepared from each composite and polymerized with an LED light device in standard power mode (1000mW/cm2) in accordance with the manufacturer's instructions. To investigate the possible effects of N-Acetyl-L-cysteine (NAC); additional three composites test groups were prepared which include %1 NAC by weight. Our study was conducted with mouse fibroblast cell line (L929). Cellular cytotoxicity was evaluated after 24 hours with WST-1 assay with direct contact test and the levels of apoptotic markers (caspase 3, caspase 8 and annexin 5) were determined by using RNA extraction kit of PCR test. Significance level is determined 0.05 in all analysis. Results: The results of WST-1 assay has shown that there was not any cytotoxic effects. Increases of cell populations were observed in Filtek Ultimate Flowable, PermaFlo Pink and PermaFlo Pink+NAC groups. Compared to the control group, a significant decrease was observed in Caspase 3 levels in all groups except the 3M Filtek Ultimate group with 1% NAC supplementation (p<0.05). When Caspase 8 levels were analyzed, when compared with the control group a significant statistical depression was detected (p<0,05). Higher annexin V activities were detected in the Filtek Ultimate Flowable and VOCO Amaris Gingiva group compared to the control group (p<0.05). Conclusions: None of the tested composites produced a direct cytotoxic effect on L929 mouse fibroblast cells as a result of the 24-hours direct contact test. The materials affected the apoptotic process by causing various changes on caspase 3, caspase 8 and annexin V levels on the apoptotic pathway. It was concluded that the addition of 1 % NAC by weight was not sufficient to suppress these effects. Keywords: Gingival composite, cytotoxicity, NAC, caspase 3, caspase 8, annexın V