The posterior maxilla is challenged with postextraction alveolar bone resorption and pneumatization drive of the Schneiderian membrane that reduces the subantral distance. To overcome such anatomic obstacle a sinus augmentation procedure was introduced either via lateral or crestal approach depending on residual ridge height. The current study evaluated oxidized regenerated cellulose (ORC) as a grafting material versus osteon II by measuring bone gain and graft density, 24 weeks postoperatively. Twenty consecutive patients (24 cases) aged from 20 to 65 years were considered eligible after clinical and radiographic evaluation. These patients were allocated in 2 groups (study and control) that underwent transcrestal osteotome antral membrane balloon elevation and surgical void augmentation with ORC in the study group, while the control group grafted with collagen membrane and osteon II with simultaneous dental implant placement in both groups and were followed up for 1 year. Cone beam computed tomography was taken for all patients preoperatively and postoperatively to verify neoformed bone and density in Hounsfield units (HU). The mean gained height of the bone was 6.48 mm (5.94 mm in the study and 7.02 mm in the control). The mean density of graft above implant apex was 497.99 HU (434.23 HU in the study and 561.75 HU in the control). Apart from Schneider membrane thickening in 2 patients from the control group, there were no serious complications reported throughout the study. These results demonstrate that ORC is a reasonable grafting material with comparable outcomes when compared to osteon II with less postoperative complications.