Comparative transcriptome analysis of periodontitis and peri‐implantitis in human subjects

Abstract Background Peri‐implantitis is similar to periodontitis, but there are some differences. For the effective control of peri‐implantitis, it is necessary to clarify its similarities and differences with periodontitis in terms of gene expression. Methods This cross‐sectional study included 20 participants (10 healthy subjects and 10 patients with periodontitis and peri‐implantitis). Gingival tissue samples (10 healthy, 10 periodontitis, and 10 peri‐implantitis tissues) were collected, RNAs were extracted, and RNA sequencing and analysis were performed. Results Differentially expressed gene (DEG) analysis identified 757 upregulated and 159 downregulated genes common between periodontitis and peri‐implantitis. Periodontitis tissues uniquely showed 186 overexpressed and 22 suppressed genes compared with peri‐implantitis and healthy tissues, while peri‐implantitis had 1974 and 642, respectively. Each common and unique differential gene set showed distinct enriched biological features between periodontitis and peri‐implantitis after the pathway enrichment analysis. The expression pattern of selected DEGs focused on the representability of the disease was validated by RT‐qPCR. Conclusions Although periodontitis and peri‐implantitis showed common gene expression that was clearly differentiated from healthy conditions, there were also unique gene patterns that were differentially expressed only in peri‐implantitis. These findings will help elucidate the mechanisms involved in the progression of peri‐implantitis.