Objectives The aim of this study was to compare bone block grafts fixed at a distance (BBG‐D) with the SonicWeld Rx shell technique (Poly‐D‐L‐Lactide foil fixed at a distance, augmented with autogenous and deproteinized bovine bone particles (SWST)) for lateral alveolar ridge augmentation. Methods In this single‐blinded, randomized, controlled trial, 30 patients with a bucco‐palatal bone width of ≤3 mm were randomized into the treatment groups: “BBG‐D” and “SWST”. Bone width was measured with cone beam computed tomography (CBCT). One implant was placed at each grafted site. Frequencies of complications, bone gain and bone resorption in the CBCT were assessed as outcomes. Results Fifteen sites were augmented in each treatment group. One graft (7%) in the BBG‐D group and five (33%) in the SWST group were lost (p = 0.17). In the SWST group, two implants (20%) were lost and none in the BBG‐D group (p = 0.18). The rate of pooled severe complications (loss of graft and/or implant) was different (p = 0.035). Five (33%) wound dehiscences happened in the SWST group and none in the BBG‐D group (p = 0.042). Seven (47%) nonsevere complications (wound dehiscence, inflammation, transient nerve injury) happened in the SWST group and one (7%) in the BBG‐D group (p = 0.035). At the one‐year evaluation, there were no significant differences in bone loss at the mesial, distal or buccal implant shoulder between treatment groups. Conclusions Within the limitations of this study, the BBG‐D method remains the gold standard for lateral alveolar ridge augmentation compared to the shell technique because of the lower complication rates.