Purpose: Using panoramic radiograph and CBCT to compare the measurement errors of the residual bone height in the same site before implant placement in the posterior maxilla and endo-sinus bone gain after osteotome sinus floor elevation without grafting, and to evaluate endo-sinus bone augmentation before stage-two surgery with CBCT. Also, some related factors of new bone formation in the sinus were analyzed, such as small bone block elevated by osteotome at the implant apex intraoperatively.
Materials and Methods: Patients were enrolled in the retrospective study; dental implants were placed in the maxillary posterior region using osteotome sinus floor elevation without grafting. The panoramic radiograph and CBCT were taken preoperatively, immediate postoperatively, and before the stage-two surgery. Endo-sinus bone augmentation was evaluated. A generalized linear model was made to explore the related factors of endo-sinus bone gain. Also, some clinical indexes, such as sinus membrane perforation rate, implant success, and failure criteria were assessed.
Results: One hundred two dental implants were inserted in 91 patients. Preoperatively, the mean residual bone height was 8.53 ± 1.76 mm and 7.87 ± 1.45 mm measured using a panoramic radiograph and CBCT, respectively, with significant statistical differences (P < .05). Endo-sinus bone gains of 1.31 ± 1.05 mm by panoramic radiograph and 1.80 ± 1.72 mm by CBCT were observed, with statistically significant differences (P < .05). The final endosinus bone gain was positively correlated with the implant protrusion length at baseline without any other relevant factors, such as elevated small bone block.
Conclusion: Measurement errors could be relatively minimized when using CBCT. Using the osteotome sinus floor elevation technique without grafting, approximately 2 mm of endo-sinus bone could be acquired. The final endo-sinus bone gain was positively correlated with implant protrusion length at baseline. Small bone block elevated intraoperatively did not gain more endo-sinus bone.