Objectives To volumetrically compare guided bone regeneration (GBR) with connective tissue graft (CTG) to reestablish convexity at the buccal aspect of single implants. Materials and methods Patients with a single tooth gap in the anterior maxilla and horizontal alveolar defect were enrolled in a single-blind randomized clinical trial (RCT). All sites had a buccopalatal bone dimension of at least 6 mm, received a single implant, and were randomly allocated to the control (GBR) or test group (CTG) to reestablish buccal soft tissue convexity. Patients received a provisional crown at 3 months and a permanent crown at 6 months. Primary outcomes were volumetric increase (mm(3)) and linear increase (mm) in buccal soft tissue profile (BSP) within a well-defined area of interest at fixed time points. Alveolar process deficiency was a secondary outcome. Results Twenty-one patients were included per group (control: 11 females, mean age 51; test: 9 females, mean age 48). After 1 year, GBR resulted in a significant volumetric increase of 20.74 mm(3)(P< .001) corresponding to linear increase in BSP of 1.30 mm (P< .001). For CTG, this was 15.86 (P< .001) and 1.19 mm (P< .001), respectively. The changes over time in volume (P= .173) and BSP (P= .241) were not significantly different between the groups. Twenty-nine percentage and 26% of the final volumetric increase was the result of installing and altering prosthetic components in the control and test groups, respectively. Alveolar process deficiency significantly reduced from pre-op to 1 year following GBR (P< .001) and CTG (P< .001). The difference between the groups was not significant (P= .342). However, 58% of the patients treated with GBR and 38% treated with CTG failed to show perfect soft tissue convexity at the buccal aspect. Conclusion GBR as well as CTG are effective in reducing horizontal alveolar defects for aesthetic purposes. However, in about half of the cases, either strategy failed to optimally reestablish buccal convexity.