Bone Material Comparison in Maxillary Sinus Augmentation

Hard and soft tissue deficiencies of an alveolar ridge arise as sequelae of tooth extraction when socket preservation is not applied. In addition, extraction of posterior maxillary teeth causes pneumatization of the maxillary sinus in relation to other fixed landmarks such as the teeth. These anatomic sinus limitations and alveolar bone deficiencies are the main challenges for dental implant placement. Different bone substitutes have been used to augment bone in pneumatized maxillary sinuses. Scaffolding materials such as xenografts or synthetics substitutes have been proven to be a viable alternative. Xenografts are obtained from nonhuman species and serve as a scaffold for the formation of new bone (osteoconduction). Histologic evaluation of maxillary sinuses grafted with xenografts revealed newly formed bone to be mostly woven bone with some remodeling to lamellar bone. These histologic findings reaffirm the osteoconductive ability of xenografts when used as the sole grafting material in maxillary sinus augmentation. Xenografts appear to be an effective method for maxillary sinus grafting and demonstrate limited resorption over time. Sinuses augmented with synthetic bone substitute (SBS) also appear to successfully integrate based on recent histomorphometric studies. Vascularization and trabecular bone formation in sinuses grafted with SBS has been previously demonstrated. One type of SBS includes porous granules of bioactive and resorbable silica-calcium phosphate nanocomposite (ShefaBone). ShefaBone grafts offer a novel alternative that can potentially unite the 3 salient bone-forming properties (osteoinduction, osteoconduction, and osteogenesis). ShefaBone has unique properties including: 1) bioactivity 2) bioresorbablility, and 3) allowing for the uptake of calcium ions from the physiological solution and releasing phosphate and silicate ions which aid in bone formation. A material with such properties will substitute bone in a more controlled and effective combination that can be obtained in many clinical situations, without the disadvantages found with autograft. ShefaBone has demonstrated successful regenerative properties for bony defects. To our knowledge, there is no reported clinical studies on the use of SCPC material to graft a pneumatized maxillary sinus. This aim of this current study is to compare SCPC to commonly used xenograft material in an augmented maxillary sinus.

1. To assess the quality and quantity of the maxillary sinus bone prior to the placement of dental implants and subsequent restorations, approximately 20 patients will be randomly assigned to receive an augmentation of the maxillary sinus region using either Shefabone (synthetic bone) or Bio-Oss (xenograft). 2. With the use of pre-operative and post-operative limited view CBCT (cone-beam computed tomography) radiography, the maxillary sinus bone density will be assessed and compared between the individuals receiving Shefabone and the individuals receiving xenograft material. 3. Histomorphometric analysis will be used to assess, compare and contrast the quality and the quantity of the new vital bone cells generated when using these different graft materials.