Mapping the Expression Profile of MicroRNA in Peri-Implantitis: A Scoping Review

Peri-implantitis remains a major biological complication compromising implant longevity. Conventional diagnostic tools, including clinical probing and radiographic evaluation, are limited in detecting early disease activity. MicroRNAs (miRNAs) have emerged as potential biomarkers due to their regulatory role in inflammation and bone metabolism.

This scoping review aimed to map the available evidence on miRNA expression profiles in peri-implantitis, identify knowledge gaps, and highlight miRNAs with potential diagnostic and therapeutic relevance.

The review was conducted in accordance with Arksey and O'Malley's framework, Joanna Briggs Institute guidelines, and PRISMA Extension for Scoping Review (PRISMA-ScR) standards. Electronic databases (PubMed, Embase, and Web of Science) were searched up to October 2025. Studies evaluating miRNA expression in peri-implantitis using human or relevant experimental samples (peri-implant crevicular fluid [PICF], saliva, gingival tissue, serum) were included. Data were extracted and synthesized narratively.

Eleven studies published between 2017 and 2025 were included. Dysregulated miRNAs were consistently associated with inflammatory and osteolytic pathways, including NF-κB, MAPK, Wnt/β-catenin, and RANKL signaling. Downregulation of miR-21-3p, miR-150-5p, and miR-4484, and upregulation of miR-155 and miR-146a were frequently reported in peri-implantitis. Polymorphisms such as miR-155 rs767649 and miR-27a-3p rs895819 were linked to disease susceptibility. However, heterogeneity in study design, small sample sizes, and lack of longitudinal validation were common limitations.

The mapped literature indicates that miRNA expression is altered in peri-implant disease across several biological compartments, but the evidence remains heterogeneous and largely exploratory. Specific miRNAs should be regarded as candidate biomarkers requiring independent and prospective validation rather than established diagnostic tools. Standardized sampling and analytical methods, clearly defined disease criteria, adequately powered longitudinal cohorts, and external validation are needed before clinical translation can be assessed.