Purpose: Peri-implantitis, a potentially progressive disease that occurs in patients with dental implants, is more aggressive than periodontal lesions, which makes the prevention of peri-implantitis an important priority. Due to problems in the early detection of peri-implantitis, there is an urgent need for discovering novel biologic molecules with the ability of early diagnosis. The goal of this study was to profile the microRNA content of saliva samples collected from patients with titanium-aluminum-vanadium alloy dental implants who experienced peri-implantitis and to find potential diagnostic markers for detection of this disease.
Materials and Methods: The microRNA expression profiles of eight saliva samples (four collected from patients with peri-implantitis, four collected from patients who have successful implants) were investigated, and the deregulation of select microRNAs was further confirmed using quantitative polymerase chain reaction.
Results: The expressions of 179 microRNAs were found as deregulated in the saliva of peri-implantitis patients in comparison to controls. Then, downregulation of miR-4484 was confirmed in the saliva of peri-implantitis patients in a larger validation cohort. Also, 40% of non-peri-implantitis patients and 78% of peri-implantitis patients had significantly decreased miR-4484 expression in saliva samples collected after 4 to 6 months subsequent to implant placement compared with samples collected before implant placement.
Conclusion: Considering these findings, microRNA content of saliva might be proposed as a plausible source for the early diagnosis of peri-implantitis, where miR-4484 might serve as an encouraging early diagnostic biomarker.