This investigation evaluated the predictability of dental implants subjected to bone regeneration procedures at the time of insertion. Fifty-two test implants were inserted into sites with periimplant bone defects. A calcium carbonate allograft material with or without a fibrin-fibronectin sealing system was used to fill the defects. Sixty control implants were inserted into an adequate volume of nonaugmented bone. Each of the 29 study patients received at least one test implant and one control implant. At the second-stage surgery, fill of the bone defect was assessed as complete or incomplete. The cumulative success rate was 91.7% (mean follow-up 55 mo) for the test implants and 93.2% (mean follow-up 59 mo) for the control implants. Within the test group, implants with complete bone fill achieved 97.6% success versus 59.1% success for implants with incomplete bone fill. These preliminary results suggest that implants placed with simultaneous bone regeneration procedures achieve long-term predictability that is comparable to that of implants placed in an adequate volume of bone, provided that complete bone fill of the periimplant defect is achieved. Long-term studies with other augmentation materials are needed to fully validate these findings.