To evaluate retrospectively at 10 years the marginal bone levels around implants located in healed ridges or in extraction sockets and loaded immediately with provisional crowns fixed in prefabricated abutments. Forty-two implants were placed in 36 patients needing single tooth replacement. Implants were inserted either in healed ridges (group 1) or in extraction sockets (group 2) and loaded immediately with prefabricated abutments. Two implants were lost during the healing period from group 2. The bone level around the implant shoulder was calculated mesially and distally on each implant using intraoral radiographs after crown cementation and 1, 3, 5, and 10 years following loading. On the 10-year follow-up report, 36 implants were available for the clinical and radiologic evaluation. Besides the two implants lost during the osseointegration period, no implant loss was documented over the 5- to 10-year observation period. The average bone loss after implant and crown cementation was 0.266 ± 0.176 mm for 1 year, 0.194 ± 0.172 mm for 5 years, and 0.198 ± 0.165 mm for 10 years in healed ridges and 0.267 ± 0.161 mm for 1 year, 0.213 ± 0.185 mm for 5 years, and 0.287 ± 0.194 mm for 10 years in extraction sockets. Three crowns (in group 1) and one crown (in group 2) were replaced for esthetic reasons. The outcome of this study revealed that in both groups, the responses of marginal bone were similar. Immediate placement of the definitive prefabricated abutment in an immediate loading protocol appears to conserve marginal bone around the implant neck.