Impact of biomaterials on intra-sinus bone changes around dental implants following indirect sinus augmentation: A randomized clinical trial

AIM: This study aimed to evaluate and compare the effect of different biomaterials - without graft, venous blood, injectable platelet-rich fibrin (i-PRF), and synthetic graft on peri-implant intra-sinus bone changes around dental implants following indirect sinus lift using the Crestal Approach Sinus Kit (CAS Kit), assessed three-dimensionally using cone-beam computed tomography (CBCT) at baseline and after 6 months. SETTINGS AND DESIGN: A randomized clinical trial was conducted at the Department of Prosthodontics, involving 64 patients aged 18-60 years with residual crestal bone height of 4-6 mm. MATERIALS AND METHODS: Sixty-four participants were randomly allocated into four groups ( n = 16 each): without graft, venous blood, i-PRF, and synthetic graft using a computer-generated randomization sequence prepared by an independent investigator. Allocation was concealed by sequentially numbered, opaque, sealed envelopes. Indirect sinus lift was performed using the CAS kit, and implants were placed simultaneously via a crestal approach. Intra-sinus peri-implant bone changes at the implant apex and at the buccal and palatal aspects (apex, middle, and sinus floor levels) were assessed using CBCT at baseline and after 6 months. Implant survival was evaluated as a secondary outcome. Descriptive statistics (mean ± standard deviation) were calculated, and intergroup comparisons were performed using the one-way analysis of variance. Statistical significance was set at P < 0.05. STATISTICAL ANALYSIS USED: Descriptive statistics (mean±SD) were calculated, and intergroup comparisons were performed using one-way ANOVA. Statistical significance was set at P < 0.05. RESULTS: In coronal sections, Groups 1 and 2 (without graft, venous blood) showed minimal and comparable bone gain. Group 3 (i-PRF) demonstrated moderate improvement, while Group 4 (synthetic graft) achieved the highest bone values, particularly at the apex, buccal-apical, and palatal-apical sites. Analysis confirmed that Group 4 significantly outperformed all others, and i-PRF consistently exceeded without graft and venous blood. Sagittal analysis showed a similar pattern: Groups 1 and 2 displayed negligible change, Group 3 had intermediate gains, and Group 4 demonstrated substantial bone formation, especially at mesial and distal apical sites. No implants were lost during the 6-month follow-up. CONCLUSIONS: Synthetic grafts demonstrated the greatest intra-sinus bone gain at 6 months. This increased bone formation may enhance apical bone support and potentially improve implant stability in cases with limited residual bone height. I-PRF showed moderate bone gain, which, although statistically inferior to synthetic grafts, may still be clinically beneficial as a cost-effective and autologous adjunct. Thus, while synthetic grafts provided the highest statistical and clinical benefit, i-PRF may serve as a clinically viable alternative when synthetic grafting is not feasible.