Purpose: The aim of this study was to evaluate the influence of the implant diameter on marginal bone remodeling around dental implants replacing single molars after a follow-up period of 3 to 6 years. Materials and Methods: Patients who received dental implants with an external hexagon platform in healed sites to support a single metal-ceramic crown in the molar region were recalled to the office. The implantation sites and implant length information were recorded, and the implants were divided according to the implant diameter: regular (RP) or wide (WP). Each implant was assessed by digital periapical radiography, using a sensor holder for the paralleling technique. The marginal bone remodeling was determined as the distance from the implant platform to the first bone-to-implant contact, and the known implant length was used to calibrate the images in the computer software. The follow-up measurements were compared with those obtained from the radiograph taken at the time of prosthetic loading to determine the late bone remodeling. The independent t test was used to compare data. Results: A total of 67 implants from 46 patients were evaluated with a mean follow-up period of 4.5 ± 1.0 years. The RP group comprised 36 implants from 29 patients (mean age: 58.3 ± 10.6 years), while 31 implants from 17 patients (mean age: 56.9 ± 11.5 years) were included in the WP group. The RP group presented lower survival rates (86.1%) than the WP group (100.0%). Similar marginal bone loss (P .05) was identified for the RP and WP groups (1.35 ± 0.96 mm and 1.06 ± 0.70 mm, respectively). Conclusion: Although wide-diameter implants exhibited lower incidence failures, the bone levels were similar after the prosthetic loading around regular- and wide-diameter implants supporting single molar crowns. Keywords: bone loss, dental implants, osseointegration