Four-Year Outcomes of Immediately Loaded Full-ArchMaxillary Dental Implants with Hybrid Versus Roughened Surfaces: A Split-Mouth Randomized Controlled Trial

<b>Background/Objectives:</b> The aim of this randomized control trial was to compare crestal bone levels from two implant types featuring surfaces of differing roughness after 4 years of follow up. The first implant type featured a hybrid surface: a minimally rough machined surface over the initial 3 mm between the prosthetic platform and the apex and a moderately rough grit-blasted surface over the remaining implant length. The second type featured a moderately rough grit-blasted surface from the implant collar to the apex and was considered as the control. <b>Methods:</b> Two of each implant type were placed in a split mouth sequence in the maxilla of 34 partially or fully edentulous patients in the original cohort. All implants were immediately loaded with either a fixed or removable denture. <b>Results:</b> Twenty-four patients with 97 implants were present at the 4-year recall, and 3 failed implants were recorded (implant survival rate = 96.9%). No statistically significant difference in crestal bone loss was found between the test and control implant types at the 4-year evaluation. <b>Conclusions:</b> Considering the sample size-related limitations of this randomized controlled trial, both hybrid and moderately rough implants showed minimal bone loss over a 4-year follow up period. While these results would suggest comparable stability over the longer term, the limited sample size prevents definitive conclusions from being made regarding clinical superiority and broader generalizability of the results. A larger, adequately powered study is warranted to confirm these findings.