A prospective cohort study of 45 nonsmoking consecutively admitted patients was studied for the treatment outcomes following jaw bone augmentation in conjunction with installment of oral implants. Twenty-eight patients were treated for both bone augmentation and implant treatment simultaneously, while 17 patients were treated with a staged approach with the bone augmentation being performed 6-8 months prior to implant installation. Three months following this, prosthetic reconstructions were incorporated. One year thereafter, baseline data and 3 years after reconstruction, follow-up data were obtained. Moderately low mean scores for the bleeding on probing percentage were found at baseline (24%) and after 3 years of function (17%), while the corresponding values at the implant sites were 40.6% and 52.4%, respectively. However, the modified gingival index (mGI) = 2 was found in only 4.8%, and 6.9% at the baseline and 3-year examinations. Peri-implant Probing depth (PPD) and level of attachment mean values did not vary between baseline and follow-up examinations. Only a small proportion of 1.8% yielded PPD = 6.0 mm after 3 years of function. Radiographic bone level measurements showed that 18.2% of the implants lost 0.5 mm during the observation period. Seventy percent of the sites were considered completely stable. It was concluded that predictable treatment outcomes resulted for oral implant installation combined with or staged after jawbone augmentation. Only 6.5% of the sites had lost 1.5% crestal bone with the staged approach while 14% of the sites had lost 1.5 mm, when the implants were placed simultaneously. This suggests that the staged approach may have a lower risk for greater amounts of crestal bone loss as the simultaneous approach. In general, crestal bone loss encountered in the present study corresponded very well with that reported following placement of the same implant system into nonaugmented bone.