Objective:To investigate the expression of miR-146a and miR-155 in gingival crevicular fluid (GCF) of patients with peri-implantitis and their relationships with bone resorption.Methods:80 implants of 80 patients with peri-implantitis from October 2015 to December 2018 were selected as the disease group and 80 implants of 80 peri-implant healthy persons checked at the same time were selected as the control group. The GCF of the examined teeth was collected with moisture absorbent paper tips; the expression levels of miR-146a and miR-155 in GCF were detected by quantitative real-time polymerase chain reaction (qRT-PCR); the alveolar bone absorption around the implant was measured by X-ray; the levels of inflammatory factors such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), osteopontin (OPN) in GCF were detected by enzyme-linked immunosorbent assay (ELISA); Pearson method was used to analyze the expression levels of miR-146a and miR-155 in GCF and their correlations with bone resorption, IL-1β, TNF-α and OPN levels.Results:Compared with control group, probe depth (PD) (4.56±0.73)mm, plaque index (PLI) (2.21±0.44), sulcus bleeding index (SBI) (2.69±0.32), bone resorption (1.86±0.34), and miR-146a (2.46±0.43), miR-155 (4.20±0.57), IL-1β (75.48±10.29)ng/ml, TNF-α (54.16±9.23)ng/ml and OPN levels (252.41±42.03)pg/L in GCF were significantly higher than those in the disease group [(1.47±0.26)mm, (1.02±0.19), (0.94±0.21), (0.47±0.09), (0.97±0.16), (1.03±0.21), (44.52±8.14)ng/ml, (21.45±4.27)ng/ml, (181.91±36.28)pg/L] (all P<0.05). Pearson analysis showed that the levels of miR-146a and miR-155 in GCF of patients with peri-implantitis were positively correlated ( r=0.558, P<0.05), and they were correlated with bone resorption, IL-1β, TNF-α and OPN levels respectively ( r=0.554, 0.606, 0.521, 0.499; 0.515, 0.653, 0.585, 0.542; all P<0.05). Conclusions:MiR-146a and miR-155 are highly expressed in gingival crevicular fluid, which are positively correlated, and may affect bone resorption in patients with periimplantitis through inflammatory reaction.

This article analyzed the specific path of iron overload affecting EMT "blood countercurrent cell survival/adhesion/invasion/angiogenesis ectopic lesions" from the three aspects of mediating NF-κB and inflammatory reaction, stimulation of abnormal activation of macrophages, and induction of oxidative stress injury; introduced the theoretical connotation of the pathogenesis of "cold coagulation and blood stasis", and briefly described the progress of the pathogenesis of EMT from the perspective of "blood out of menstruation - injury caused by cold pathogenic factors - cold coagulation and blood stasis - long-term accumulation syndrome"; based on the mutual confirmation of "menstruation countercurrent - iron overload microenvironment - cell survival/adhesion/invasion/angiogenesis - ectopic focus" and "blood out of menstruation - cold pathogen injury - cold coagulation and blood stasis - chronic accumulation syndrome", it was believed that starting from iron overload could tap the scientific connotation and microscopic materials of the pathogenesis of "cold coagulation and blood stasis" in EMT, so as to provide new directions and theoretical references for the research of the pathogenesis of EMT and the mechanism of drugs.