Aim: The aim of this study is to investigate the crestal bone loss around the implants following guided bone regeneration in dehiscence and fenestrations and its effect on peri-implant health after a period of five years. Materials and Methods: A total of 41 consecutively treated patients who had received bovine particulate bone augmentation Endobon® (Biomet 3i) were evaluated in a single center. From this cohort, 13 patients were enrolled in the study and the others were drop-outs. 17 implants were installed in the patients. The patients were contacted 5 years after implant loading. All patients had undergone periapical radiographs and orthopantogram immediately after crown installation T0 and then 5 years after placing the implants T1. Digital and analog radiographs were evaluated by one clinician from the patient charts after the crown installation. The periodontal chart was taken, pocket depth, bleeding on probing and plaque amount was scrutinized around each implant. Statistical analysis was performed using SPSS software Results: All implants survived after 5 years of loading. Significant bone loss was revealed between the baseline and the follow-up time at the implant sites. The overall mean bone loss at the implant site was 0.69 (SD: 0.73). On the mesial side for all but two implants (0.03 and 0.04) the evolution was toward bone loss. On the distal side for all but three implants (0.01, 0.02, 0.02) the evolution was toward loss of bone. No difference in the bone loss was seen between mesial and distal sites. 87.5% of the implant sites with bone augmentation showed bleeding on probing. The plaque was seen in 31.3% of the implant sites Conclusion: Bone augmentation with bovine bone hydroxyapatite in one stage implant surgery remained stable during the 5 years follow-up around the minimally rough implants used in this study. However, the amount of bone loss and mucositis at the implant sites with GBR remained significantly high.