This study examined the outcomes of using the Crestal Approach Sinus (CAS) kit alongside tissue-level implants for sinus augmentation in patients with limited bone height. It also evaluated the bone thickness above the implant tip to determine safety and effectiveness of this minimally invasive technique. Data from 15 patients (20 implants) treated between September 2021 and October 2024 were analyzed. All cases had at least 2 mm of residual bone in the posterior maxilla. Preoperative CBCT scans assessed initial bone conditions, and panoramic X-rays tracked changes at the time of implant placement and nine months post-procedure. Primary measures included implant survival and complications, while secondary measures focused on vertical bone gain and bone coverage over the implant apex. Wilcoxon signed-rank tests were used for statistical comparisons with a 0.05 significance threshold.
All implants integrated successfully, with no failures or complications reported. Initial bone height averaged 4.2 ± 1.4 mm, increasing to 13.8 ± 1.8 mm after sinus elevation. At nine months, membrane elevation slightly decreased to 13.0 ± 1.6 mm, yielding an average bone gain of 9.6 ± 2.4 mm. Bone above the implant tip reduced from 3.4 ± 1.7 mm to 3.0 ± 1.2 mm (p = 0.007). The CAS kit combined with tissue-level implants appears to be a safe and effective minimally invasive approach for sinus lifts, producing reliable bone gain and excellent implant survival. These findings support its use in patients with limited residual bone, although larger studies with longer follow-up are recommended.
