Investigation of the mediator levels showing the activation of the complement system's classic, lectin-dependent and alternative pathways in gingival crevicular fluid and peri-implant crevicular fluid

Objective: In this thesis study, it was aimed to investigate biomarkers showing the activation of classical, alternative and lectin-dependent pathways of the complement system in gingival crevicular fluid (GCF) and peri-implant crevicular (PICF) samples obtained from individuals with stage 3-degree B periodontitis and peri-implantitis. Method: A total of 45 individuals in 3 groups, including 15 periodontally healthy individuals, 15 patients diagnosed with Stage 3-Grade B periodontitis and 15 patients diagnosed with peri-implantitis were included in this study. GCF and PICF samples were collected before Phase-1 treatments of the patients. The samples were analyzed by ELISA (Enzyme Linked Immunosorbent Assay) method. C1q protein to evaluate classical pathway activation, MBL and MASP-1 proteins to evaluate lectin-dependent pathway activation and CFB protein to evaluate alternative pathway activation in GCF and PICF samples in all groups. In addition, C3C, C3a, C5C and C5b-9 proteins were evaluated which are involved in all pathways of the complement system. Results: Although there is no statistically difference between the groups in terms of gender, there is a statistically significant difference in age. When buccal and palatinal / lingual clinical attachment level (CAL), gingival index (GI) and plaque index (PI) were evaluated; the healthy group was lower than the Stage 3-Grade B periodontitis and peri-implantitis group (p <0.05). When C1q, MBL, CFB and C3C levels were evaluated, no statistically significant difference was found between the groups. When MASP-1 and C5b-9 levels were evaluated; they were statistically lower in the healthy group than the Stage 3-grade B periodontitis and peri-implantitis groups (p˂0.05). When C3a levels are evaluated; the peri-implantitis group was significantly lower than the healthy and Stage 3-grade B periodontitis groups (p˂0.05). When C5C levels were evaluated, the peri- implantitis group was found to be significantly higher than the healthy and Stage 3-grade B periodontitis groups (p˂0.05). Conclusion: In this study, no dominance of any pathway was observed in the activation of the complement system in GCF and PICF samples collected from individuals with periodontitis and peri-implantitis. However, it can be thought that the complement system have an important role in the pathogenesis of periodontitis and peri-implantitis.