The aim of the present prospective and preliminary study was to compare the clinical and radiographic outcomes of 2 types of rough surfaced implants after implant placement in the atrophic posterior maxilla with sinus membrane elevation without bone grafting using the crestal approach. All clinical and radiographic records for 28 patients who had received 40 implants were included in the present study. The patients returned for radiographic and clinical examinations at 1, 3, and 6months and every 6months thereafter after implantation. Cone-beam computed tomography images were taken to evaluate the amount of bone gain in the maxillary sinus. Standardized periapical digital radiographs were taken to evaluate the changes in the crestal peri-implant bone level and peri-implant fixture radiolucency. The Kaplan-Meier survival estimates demonstrated a 100% probability of survival to 24months. No significant differences were found in cervical bone loss (CBL) or residual bone height (RBH) between the TS III CA group and the TS III SA group during the 2-year follow-up period after implant placement. The CBL values according to gender, implant placement region, prosthesis type, and the time of implantation were not significantly different between the 2 groups. The results of the present preliminary study demonstrate that 2 types of rough surfaced implants placed in the atrophic posterior maxilla with sinus membrane elevation without a bone graft have good clinical and radiographic outcomes.