SINUS LIFT 100% Anorganic Bovine Bone vs. 50% Anorganic Bovine Bone + 50% Autologous Bone

Background: Maxillary sinus floor augmentation is a standard surgical procedure to increase bone height in the atrophic posterior maxilla for dental implant placement. In bone reconstructive surgery, in general, autogenous bone is considered as the gold standard, primarily due to its osteogenic potential and remodelling capacity. Bone substitutes are available that can overcome the limitations of autologous bone due to their osteoconductive properties and biocompatibility. Several studies seem to validate these concepts, but further comparative trials are needed. Aim: To compare the outcome of implants inserted in maxillary sinuses augmented with bovine bone grafts vs 50% bovine bone graft and 50% autologous bone according to a lateral approach. Material and Methods: This study was designed as a randomised, controlled, clinical trial. Sixteen partially or fully edentulous patients, 20 sinuses, (four patients have been bilaterally treated) having 1 to 4 mm of residual crestal height below the maxillary sinuses were randomised according to a parallel group design. Sinuses were grafted according to a lateral approach. Group A (10 sinuses) was grafted with 50% anorganic bovine bone (Bio-Oss) and 50% autogenous bone, group B (10 sinuses) was grafted with 100% anorganic bovine bone (Bio-Oss). According with a two stages approach, after 7 months a total of 32 implants (Nobel Replace tapered groovy) were inserted with an insertion torque between 35 and 45 Ncm. At same surgical procedure a sample of bone was harvested for histomorphometric analysis . All implants were delayed loaded with screw retained temporary crowns 3 months after implants insertion and with screw retained definitive crowns 4 months later. Outcome measures were implant survival, biological and prosthetic complications, radiographic marginal bone-level changes, PPD and BOP. Clinical data were collected at baseline 6,12 months. Statistical significance was tested at the 0.05 probability level, and all val