Valutazione della stabilità dell'innesto osseo nel rialzo di seno mascellare, utilizzando osso bovino deproteinizzato in differenti granulometrie
Progetto Background. An inadequate bone volume and quality have been considered for many years as absolute contra-indications for implant-supported rehabilitation. The risk of implant failure was particularly high in the posterior maxilla, because of its poor bone quality and the progressive resorption caused by edentulism. In this case, implant treatment must be carefully planned and can require a pre-prosthetic surgical intervention of bone grafting. In the case of insufficient crestal bone height at posterior maxilla level, maxillary sinus floor augmentation is often performed to create conditions adequate for placing implants. Many different types of graft materials have been used over the years, but autogenous bone has long been considered the gold standard due to its osteogenic, osteoconductive and osteoinductive properties. One of the drawbacks of autogenous grafts is their considerable resorption over time, leading to subsequent sinus repneumatization and/or implant failure due to reduction of the actual graft volume functional to implant rehabilitation. Graft volume reduction over time is less pronounced with many bone substitutes, among which anorganic bovine bone proved to be particularly effective. This material is available as blocks or granules of variable size and it would be interesting to know which type of granules display the lower resorption rate over time.
Methods. This will be a prospective randomized split-mouth clinical trial. Patients with edentulous posterior maxillae undergoing bilateral maxillary sinus augmentation procedure will receive grafts consisting of small (0.25-1mm size) granules of Bio-Oss (test) on one side and large granules (1-2mm size) of anorganic bovine bone (control) on the opposite side. 20 patients (40 sinuses) will be treated. Computerized tomography (CT), orthopantomograms (OPT) and software programs will be used to obtain images of the maxillary sinus and the adjacent antral floor. Detailed cross-sectional CT scans allow calculation of the augmentation volume required while OPTs allow estimation of graft height. Both radiographic techniques are useful to evaluate graft volume stability over time.
Aim. To evaluate from a radiological point of view, the graft volume stability up to 18 months after maxillary sinus augmentation surgery using anorganic bovine bone with different particle size (0.25-1 mm Vs. 1-2 mm) as the graft material.