Porous c.p. Titanium Using Dextrin as Space Holder for Endosseous Implants

Porous structures are advantageous alternatives to bulk titanium for endosseous implants because the elastic modulus can be adjusted to match that of bone, preventing bone retraction. Porous titanium scaffolds were developed using corn starch dextrin powder with increased granularity to obtain larger pores. Titanium and dextrin powder mixtures in different proportions (15, 25, 35 and 40% dextrin) were die-pressed and sintered under high vacuum. The porosity of the implants was between 21.80 and 37.79%. The surface of porous titanium was characterized by SEM analysis that showed presence of pore sizes over 100 mu m for all compacts, except those with 15% dextrin. For samples with 35 and 40% dextrin, the size of pores reached 200-250 mu m. X-ray diffraction analysis of titanium samples revealed presence of TiOCN compound with progressive increase with dextrin content. Mechanical characteristics were investigated by compression tests. Osteoblasts adhesion and proliferation was determined by MTT assay and scanning electron microscopy (SEM) analysis. Expression of proteins involved in differentiation and cell adhesion osteopontin (OPN) and intercellular adhesion molecule 1 (ICAM-1) were investigated by immunocytochemical staining. Implants that met both mechanical conditions closest to the bone and improved biocompatibility were samples with 35 and 45% dextrin, recommending their use in bone tissue engineering.