MicroRNAs and Cytokines in Peri-Implantitis Tissue

Peri-implantitis is a non-linear and accelerating pattern of loss of supporting bone tissue associated with clinical signs of inflammation and increased probing depths compared to baseline measurements. It can present as an asymptomatic condition with infection and fast progression of bone resorption or clinically symptomatic with mucosal inflammation, redness, edema, mucosal enlargement, bleeding on probing (BOP), suppuration, increased probing depth, and radiographic bone loss. The host immune defense against bacterial challenge is responsible for the damage, and the local immune-inflammatory process is associated with disrupted bone remodeling. New studies looking for predictive and accurate early biomarkers for this pathology have the utmost relevance. David Baltimore et al. proposed a feedback loop involving miRNA-146a and TLR signaling, which has been shown to be up-regulated in inflammatory diseases such as osteoarthritis and rheumatoid arthritis. miRNA-146a and miRNA-155 were the first miRNAs identified to be induced in immune cells stimulated by TLRs and proinflammatory cytokines. Precision medicine uses molecular research and different biomarkers, population studies, and big data analysis to recreate complex disease models. Several studies have compared the miRNA profiles of patients with periodontitis with healthy patients. Although periodontitis and peri-implantitis share many features, researchers\' findings of periodontitis are not necessarily applicable to peri-implantitis. In fact, based on emerging evidence, peri-implantitis, and periodontitis exhibit several key differences, including their histopathological and molecular characteristics. Considering the aforementioned analysis, inflammatory miRNAs may be differentially expressed in peri-implantitis tissue compared with healthy gingival tissue. This study will investigate the gene expression levels of miRNA-146a and miRNA-155 and their correlation with inflammatory levels of their target genes in human gingival tissue surrounding dental implants diagnosed with peri-implantitis and health.