Influence of implant protrusion length and initial bone height on intrasinus bone gain in transalveolar sinus floor elevation without bone graft: a 2-year retrospective study

A transalveolar sinus lift is a safe and predictable long-term surgical approach. Several factors affect clinical and radiographic outcomes. This study aimed to evaluate the correlation between intrasinus bone gain (IBG) with the implant protrusion length (IPL) and the initial bone height (IBH) in transalveolar sinus floor elevation (TSFE) without bone graft procedures. MATERIALS AND METHODS: This retrospective cohort study was carried out on patients who had reported to the department of oral and maxillofacial surgery at Tishreen University between January 2020 and September 2022. The sample consisted of patients who had a transalveolar sinus lift with simultaneous dental implants placement. TSFE was performed using motorized threaded bone expanders. The IBH, the IPL, and the IBG height were analyzed using CBCT scans that were taken preoperatively and 6 months postoperatively. Statistical analysis was performed to assess the relationship of the IBG with the IPL and the IBH. The P values < 0.05 were considered to be statistically significant. RESULTS: A total of 34 implants were placed using motorized threaded bone expanders in 29 patients who were included in the study. Three membrane perforations were observed out of 34 procedures (8.82%). The survival rate for all implants was 100%. The mean IBH was 6.37±0.85 mm, the mean IPL was 2.01±0.55 mm, and the mean IBG was 1.69±0.44 mm. A strong positive correlation was found between bone gain and IPL. No correlation was found between bone gain and IBH. CONCLUSIONS: According to the result of this study, the IPL is a critical factor in TSFE and dental implant placement simultaneously without bone graft procedures.