Purpose: This randomized controlled clinical trial compared the stability of augmented bone between a synthetic resorbable membrane and a collagen resorbable membrane with guided bone regeneration (GBR) simultaneous with dental implant placement in the esthetic zone in terms of facial bone thickness. Materials and Methods: A total of 60 dental implants from patients requiring implant placement with simultaneous GBR in the esthetic zone were equally allocated to the test group or control group by block randomization. Biphasic calcium phosphate ceramic bone was used in combination with either a polylactic acid (PLA) membrane (test group, 30 implants) or a resorbable collagen membrane (control group, 30 implants). Cone beam computed tomographic (CBCT) images were used to assess the facial bone thickness postimplantation and then 6 months later at four levels: implant platform and 2 mm, 4 mm, and 6 mm apical to the implant shoulder. Results: All implants were osseointegrated, and no implant loss was found during this study. Facial bone was detected in all cases; however, the thickness of the facial bone was reduced at the 6-month follow-up in both groups. The percentage of facial bone thickness reduction was 34.30%, 27.94%, 24.25%, and 19.81% in the test group and 34.80%, 24.06%, 19.52%, and 20.45% in the control group at the level of the implant platform and at 2 mm, 4 mm, and 6 mm apical to the implant shoulder, respectively. Nevertheless, there was no statistically significant difference between the groups (P > .05). Conclusion: A synthetic resorbable membrane revealed an amount of stable augmented bone similar to that of a collagen resorbable membrane. Keywords: cone beam computed tomography, dental implant, facial bone thickness reduction, guided bone regeneration, resorbable membrane, stability of augmented bone