Evaluation of two composite bone graft mixtures for sinus augmentation

Objectives: To compare two different grafting materials used for sinus augmentation in terms of bone formation and clinical outcomes. Methods: Five patients underwent a bilateral sinus lift technique for the placement of implants in the maxillary area (informed written consent was obtained from patients after explaining the trial, according to a protocol approved by the Institutional Review Board). Two different grafts materials were used per patient following a half-mouth design: In the right sinus, the cortical bone overlying the sinus membrane was used as graft, in combination with bovine bone (Bio-Oss®). In the left one, the overlying autologous bone was used in combination with synthetic resorbable bone substitute (Novabone®). Bone core biopsy samples were taken for histological analysis 6 months later, at the time of implant placement. After six months fixed partial dentures (FPD) were elaborated to load the fixations. Peri-implant bone was clinically and radiographically evaluated 24 months after loading. A comparative histomorphometric analysis was made with a specific software (Image J). Pairwise comparisons were performed by Wilcoxon ranks test (p<0.01). Results: Mean percentage of each component is presented in the table. Both bone graft mixtures presented similar levels of new bone and connective tissue formation. Implants placed after sinus augmentations are functional after a 24-months period of loading in all cases. No bone loss associated with the grafts was observed either radiographically or clinically. Conclusions: Tested bone graft mixtures are equally effective for sinus augmentation surgery.