Enhanced extracellular matrix production and mineralization by osteoblasts cultured on titanium surfaces in vitro

Long-term stability of orthopaedic and dental implants depends on the integration of the artificial material into the surrounding bone tissue. The physical and chemical properties of implants, including those made of metals such as titanium, are thought to influence osseointegration. Despite the known importance of this interface, little is known about the factors that promote its formation. In this study, chick embryonic calvarial osteoblasts were cultured in vitro on smooth, rough-textured and porous-coated titanium surfaces and examined for morphology, biosynthesis of extracellular matrix and mineralization as a function of culture time. Scanning electron microscopy revealed that osteoblasts adhered securely to the titanium surface and frequently bridged the uneven surface by means of cellular processes. The osteoblast phenotype was retained in the cell cultures on titanium. In addition, the synthesis of extracellular matrix and subsequent mineralization were both substantially enhanced in the cultures on rough-textured and porous-coated titanium. These results strongly suggest that porous or rough titanium implant surfaces may act like "natural" substrata to permit microscopic tissue/cell ingrowth to improve clinical implant fixation.