Purpose: This study aimed to evaluate the radiographic bone level changes of implants positioned via the split-crest procedure both in the maxilla and mandible at a long-term follow-up. Materials and Methods: Seventy-one patients were retrospectively enrolled in the study. The placement of 137 dental implants was performed in the edentulous premolar or molar region after a split-crest ridge expansion procedure. Implants followed a delayed loading protocol. Intraoral digital radiographs were performed at baseline, upon implant placement, at 70 days (following placement of the provisional prosthesis), and on a yearly basis during followup. Crestal bone levels were evaluated at the baseline, upon provisional prosthesis placement, at 12, 36, and 60 months, and at the long-term follow-up of healing from implant placement. Results: The patients underwent a mean follow-up of 6.54 ± 1.32 years, from which the implant survival rate was reported at 98.54%. Within the first year from implant placement, a bone loss resulted at a mean value of -1.11 ± 0.44 mm. After almost 3 years from implant placement, a mean bone gain of +0.89 ± 0.39 mm was reported, which was statistically significant compared with 12-month values (P .05). From this point, bone levels remained stable, reporting similar values over time, with no significant differences (P > .05). Conclusion: A mean vertical bone gain of +0.89 ± 0.39 mm was observed after almost 36 months after implant positioning. Keywords: bone level, dental implant, split crest