Effect of Abutment Material on aMMP-8 Levels in Peri-Implant Sulcular Fluid over 12 Months: A Randomized Controlled Trial

Abstract

Background/Objectives: The long-term success of dental implants can be influenced by the material properties of abutments and their interaction with peri-implant tissues. This study investigates the impact of three abutment materials—titanium (Ti), zirconium oxide (Zr), and polymethylmethacrylate (PMMA)—on the inflammatory response in peri-implant sulcular fluid (PISF), using active-matrix metalloproteinase-8 (aMMP-8) as a biomarker. Methods: In this prospective, randomized clinical trial, 30 patients were assigned to Ti, Zr, or PMMA abutment groups. PISF samples were collected at predefined intervals over 12 months and analyzed for aMMP-8 levels using enzyme-linked immunosorbent assays (ELISA). Clinical parameters (probing depth, bleeding on probing, and plaque index) and radiographic assessments of bone resorption were also evaluated. Results: Two weeks after implant uncovering, baseline aMMP-8 levels varied significantly among materials, with Zr demonstrating the highest levels. Over time (2, 3, 6 and 12 months after implant uncovering), aMMP-8 levels decreased across all groups, with no significant differences observed at 12 months. Radiographic assessments indicated no statistically significant differences in bone resorption, with clinical parameters remaining comparable across all groups. Conclusions: Initial inflammatory responses to abutment materials may vary; however, all tested materials—Ti, Zr, and PMMA—showed long-term biocompatibility and supported healthy peri-implant tissue integration. These findings indicate that selecting any of the tested abutment materials does not significantly affect long-term peri-implant health.