Clinical and Radiographic Outcomes of Transcrestal Sinus Floor Elevation With RBH of 3-5 mm: A Retrospective Study

To evaluate the clinical and radiographic outcomes of transcrestal sinus floor elevation (TSFE) with simultaneous implant placement in sites with residual bone height (RBH) of 3-5 mm.

This retrospective cohort study included patients who underwent TSFE with simultaneous implant placement between December 2017 and September 2023. According to the intraoperative bone grafting status, patients were divided into two groups: the non-grafting group and the grafting group (Bio-Oss Collagen). Patient medical histories were collected, and radiographic parameters were measured at the following timepoints: preoperative (T0), immediate postoperative (T1), healing phase (T2, 4-6 months postoperatively), and follow-up period (T3, 1-6 years postoperatively). Implant survival rate, complication-free survival rate, incidence of sinus membrane perforation (SMP), endo-sinus bone gain volume (ESBGV), endo-sinus bone gain height (ESBGH), marginal bone loss (MBL), apical bone height (ABH), and mean cost of treatment were evaluated. A linear mixed model (LMM) regression was employed to identify key determinants influencing endo-sinus bone augmentation following TSFE.

Sixty-six dental implants placed in 57 patients were included (non-grafting group: 26 implants in 21 patients; grafting group: 40 implants in 36 patients). After the 1- to 6-year follow-up, the survival rate of implants was 100% in two groups (p > 0.05) and complication-free survival rate was 84.85% at implant level (non-grafting group: 80.77%, grafting group: 87.50%; p > 0.05) and 82.46% at patient level (non-grafting group: 76.19%, grafting group: 86.11%; p > 0.05). The incidence of SMP was 11.54% and 10.00% in non-grafting and grafting groups, respectively (p > 0.05). ESBGV, ESBGH, and ABH were significantly greater in the grafting group compared to the non-grafting group (p < 0.05). No significant differences in MBL were found (p > 0.05). The total treatment cost was significantly lower in the non-grafting group than in the grafting group (p < 0.05), whereas no significant difference was found in retreatment costs between the groups (p > 0.05). The LMM regression results showed that the core determinant of ESBGV was postoperative maxillary sinus augmentation volume (p < 0.05).

Within the limitations of this study, TSFE with simultaneous implant placement demonstrated medium- to long-term stable clinical and radiographic outcomes in the posterior atrophic maxilla ridges with RBH ranging from 3 to 5 mm regardless of bone grafting. While the grafting strategy significantly enhanced endo-sinus bone augmentation, the non-grafted approach was associated with significantly lower overall treatment costs.