Effect of different nicotine-treated implant supported provisional prosthetic materials on human gingival fibroblasts

Temporary restorations on implants meet the functional, aesthetic and phonation needs of patients during the treatment process, they play a critical role in reducing infection, bone and gum loss in the long term by supporting the directed healing of tissues around the implant. However, smoking poses a serious threat to oral health and increases the risk of failure, especially in implant and prosthetic applications. In addition, the porous structure and high absorption capacities of polymer-based materials, which are commonly used in temporary restorations, cause these materials to interact more with oral chemicals; When combined with toxic substances found in cigarette, it has the potential to further increase its biological effects on surrounding tissues. This thesis aims to investigate the effects of 4 different interim prosthetic materials (Polymethylacrylate, PMMA block, 3D printer resin and composite resin) and their interaction with nicotine on cell viability, cell attachments and extracellular matrix, tissue inhibitors, pro-inflammatory and anti-inflammatory cytokines mRNA expressions of human gingival fibroblasts (HGF). For this purpose, extracts were collected from each group for 3 and 7 days. Next, HGF cells were treated with these extracts. Cell viability experiments were performed on day 3 and day 7 by performing MTT enzymatic activity test. Total RNA was observed after 3 and 7 days of administration of supernatants 1. They were isolated on day and day 3 and their gene expression was analyzed by real-time polymerase chain reaction (RT-PCR). In addition, scanning electron microscopy (SEM) was used for the cell attachment. In experimental analyses of cell viability, a statistically significant decrease was observed in the nicotine-containing groups compared to the control groups at the end of both the 3rd and 7th days (p<0.01). In the comparisons between the groups, a more significant decrease in cell viability was found in the groups where composite and 3D printer materials were used compared to other materials (p<0.01). However, significant increases in mRNA expression levels of TNF-α, IL-6, IL-8, and IL-10 cytokines were noted in all nicotine-containing groups. In addition, variable increases were observed in IL-1β, MMP-1, MMP-2, MMP-3 and TIMP-1 and TIMP-2 gene expression levels depending on the material in the analyzes performed with the 3rd and 7th day extracts of the materials. Nicotine and temporary prosthetic materials reduced the cell viability of HGF cells, regulated the mRNA expressions of pro-inflammatory cytokines, and affected the expressions of enzymes responsible for degradation and inhibition of degradation at different levels. Key Words: 3D Printer; Biocompatibility; CAD/CAM; Human Gingival Fibroblast; Immediate Loading