Eight-Year Follow-Up of Hybrid and Moderately Rough Implants Supporting a Mandibular Overdenture: A Split-Mouth Randomized Clinical Trial.

Abstract

This split-mouth randomized controlled trial evaluated the effect of implant surface roughness (hybrid vs. moderately rough) on long-term crestal bone remodeling and peri-implant health. Oral Health-related Quality of Life (OHRQoL) was evaluated after 1 and 8 years. Twenty-four fully edentulous patients received a mandibular overdenture supported by two implants: one with a complete moderately rough (DCC) surface (Sa: 1.3 μm, Sdr: 60%) and one hybrid (MSC) implant, with a minimally rough machined surface (Sa: 0.9 μm, Sdr: 34%) at the coronal 3 mm. After 8 years, 19 patients (38 implants) were evaluated. Crestal bone loss (CBL) was measured radiographically at 1, 6, and 8 years. Plaque score, bleeding on probing (BoP), probing pocket depth (PPD), and OHRQoL (OHIP-14) were assessed at 1 and 8 years. There were no implant failures. CBL after 8 years was 0.43 mm (MSC) and 0.48 mm (DCC), with no significant difference (p > 0.05). Periodontal parameters were comparable, and the improvement in OHRQoL remained stable. Two-implant bar-retained mandibular overdentures showed high survival, stable bone levels, and sustained improvement in OHRQoL after 8 years. No differences were detected between both implant surfaces under the conditions of this study.