This study aimed to describe the step-by-step procedure of the polydioxanone dome technique associated with guided bone regeneration (GBR) and to report the results up to 72 months after implant loading. Patients with maxillary horizontal bone defects (< 5 mm residual width, confirmed by CBCT scan) were treated with the proposed intervention. During the GBR procedure, four bone perforations were strategically prepared in a roughly square configuration. Segments of polydioxanone suture material were introduced in the perforations, forming a dome-shaped structure. Six months after bone augmentation, a new CBCT was performed. After implant restoration, periapical radiographs were taken, which were then repeated annually. The following outcomes were analyzed: implant survival, horizontal bone gain, marginal bone level, and complications. Twenty implants were placed in 11 patients with a survival rate of 100% in a mean follow-up of 38.18 ± 19.65 months after loading. Mean horizontal bone gain was 3.82 ± 1.67 mm and mean marginal bone level was –0.12 ± 1.17 mm. Only minor complications were observed. The present results suggest that the polydioxanone dome technique may represent a promising approach during horizontal GBR, alone or in combination with implant placement.