**Maria Menini 1, Paolo Pesce 1,\*, Domenico Baldi 1, Gabriela Coronel Vargas 2, Paolo Pera <sup>1</sup> and Alberto Izzotti 2,3**


Received: 12 June 2019; Accepted: 18 June 2019; Published: 21 June 2019

**Abstract:** The aim of the present study is to evaluate the expression of microRNA (miRNA) in peri-implant soft tissue and to correlate epigenetic information with the clinical outcomes of the implants up to the five-year follow-up. Seven patients have been rehabilitated with fixed screw-retained bridges each supported by implants. Peri-implant bone resorption and soft tissue health parameters have been recorded over time with a five-year follow-up. Mini-invasive samples of soft peri-implant tissue have been taken three months after implant insertion. miRNA have been extracted from cells of the soft tissue samples to evaluate gene-expression at the implant sites by microarray analysis. The epigenomic data obtained by microarray technology has been statistically analyzed by dedicated software and compared with measured clinical parameters. Specific miRNA expression profiles predictive of specific clinical outcomes were found. In particular, some specific miRNA signatures appeared to be "protective" from bone resorption despite the presence of plaque accumulation. miRNA may be predictors of dental implant clinical outcomes and may be used as biomarkers for diagnostic and prognostic purposes in the field of implant dentistry.

**Keywords:** dental implants; micro-RNA; microarray; predictive biomarker; epigenomics
