Six hundred twenty-six titanium plasma-sprayed cylindrical implants that had been functioning in regenerated bone for a p eriod of up to 51 months were evaluated according to Albrektsson's criteria. These implants had been placed either with concomitant guided bone regeneration procedures or in bony ridges that had previously been augmented. According to Albrektsson's criteria, absolute success rates of 97.6% overall, 98.8% in the maxilla, and 98.2% in the mandible were recorded, as were cumulative success rates of 94.9% in the maxilla and 91.9% in the mandible. The overall cumulative success rate was 93.8%. One patient, who underwent protracted chemotherapy 14 months after implant function began, accounted for 33% (3 of 9) of the total implant loss in the study. If this patient is excluded from the study, the cumulative success rates are 94.9% (maxilla), 96.7% (mandible), and 95.8% (overal l). These findings support the theory that regenerated bone will achieve osseointegration with titanium plasma-sprayed cylindrical implants, and that this osseointegration can be maintained under function over time.