Purpose: The aim of this study was to clinically and radiographically compare the trephine core procedure and the bone-added osteotome sinus floor elevation technique in the augmentation of the sinus floor. Materials and Methods: A single site in each subject requiring sinus augmentation where the residual bone height was ~4 mm was randomly allocated to either the trephine core procedure or the bone-added osteotome sinus floor elevation technique. Measures of bone fill and bone height were also acquired through scans from cone beam computed tomography obtained before the sinus augmentation procedure (baseline) and before implant placement at approximately 6 months postoperatively. Clinical parameters for healing (early wound healing index), swelling (measurement of preset facial landmarks), and pain (through visual analog scale) were assessed at 1 week and 2 weeks after surgery. The evaluation of bone fill was performed using the digital subtraction technique and morphometric area analysis on the baseline and postoperative scans using two kinds of image processing software. Implants were placed after a healing period of 4 to 6 months, and implant stability quotient values (using SmartPeg Type 49) were recorded immediately after implant placement. Results: While both of the procedures resulted in an increase in bone fill and bone height, there were no significant differences between the techniques. No significant differences were observed between the two groups for implant stability quotient values after implant placement. No significant differences were observed between the two groups for measures of healing, swelling, and pain. Conclusion: Based upon this study that compared the trephine core procedure with the bone-added osteotome sinus elevation technique, comparing bone height, bone fill, and primary implant stability, the two procedures appeared to perform in an equivalent fashion. Keywords: dental implant, maxillary sinus, sinus floor augmentation, trephining