Cone-Beam CT Assessment of Bone Formation After Two-Stage Transalveolar Sinus Elevation Using a Hydraulic Pressure Device

ABSTRACT Insufficient residual bone height (RBH) in the maxillary molar region necessitates sinus floor elevation before implant placement. There is limited consensus on the optimal technique in cases with severe bone loss (RBH <3 mm), particularly when assessed using cone-beam computed tomography (CBCT). This study evaluated bone regeneration following two-stage transalveolar sinus floor elevation using a hydraulic pressure device in patients with <3 mm RBH, classified as SA4 in Misch's Subantral classification. Sixteen patients with a mean preoperative RBH of 1.93 mm underwent CBCT between 2018 and 2023. Six patients were excluded due to technical difficulties with device sealing, and the remaining 10 were included in the retrospective analysis. Approximately 1–1.5 cc of sterile saline solution was injected under the Schneiderian membrane using the hydraulic pressure technique. CBCT scans were obtained immediately after the procedure and after 6 months. The mean elevation height was 10.34 ± 1.83 mm immediately postoperatively and 9.17 ± 2.12 mm at 6 months. Adequate bone height for implant placement was achieved in all cases. During the 72-month follow-up period, one implant failure occurred, resulting in a cumulative survival rate of 94.7%. No intraoperative or postoperative complications, including Schneiderian membrane perforation, were observed. Within the limitations of this study, two-stage transalveolar sinus floor elevation using a hydraulic pressure device appears minimally invasive and reliable, even with severely resorbed ridges. Improved device sealing and multicenter trials are warranted.