| Since the first dental implantation was operated in1965, dental implants have become the most effective treatment for patients with denture defect and denture loss gradually. It was considered to be useful to restore the function of oral and dental system. Ultimate success of the dental implants are dependent on the solid formation of osseteo-integration, that is, reliable physical and chemical bonding between alveolar bone and implants. As the most widely used implant material in the field of dental implants, titanium shows good mechanical properties and favorable biocompatibility. However, the nature of titanium belongs to inert biomaterial. The tissue reactions were nonspecific and randomness after implantation of titanium. Long healing period is necessary for implants to bear function stress. In order to endow titanium implant material with better biocompatibility and bioactivity, titanium implant surface-modification has become the research highlights. Chemical, physical and morphological methods were used as common methods of surface modification. With the introduction of Nanotechnology in the medical engineering field, traditional materials could be modified by nanotechnology to fabricate the nanoscale materials with unique biological properties for tissue engineerin, which attracted much attention and become the research focus in dental implantology. The study fabricated an orderly arrangement layer of nanotube on titanium implant surface by anozation method. The effects of geometric scale and nanomorphology of TiO2nanotubes on cellular and tissue response were also investigated. This research is composed of three experiments. 1. Fabrication of TiO2nanotubes on titanium implant surface:TiO2nanotube layers were fabricated on the titanium surface by anodic oxidation method. The diameter of TiO2nanotube, wall thickness and surface morphology were controlled by adjusting the relative parameters. Varieties of methods were used to observe the characterics of titanium surface.2. Effects of different diameters of TiO2nanotubes on osteoblastic function: Osteoblasts were co-cultured with titanium implant materials. Effects of different diameter on osteoblast adhesion, proliferation, differentiation and osteogenesis related proteins were investigated in vitro studies. The results showed that the titanium material surface modified with TiO2nanotubes had good biocompatibility, obviously promoting osteoblast proliferation, differentiation and osteogenic protein expression. Nanotubes with100nm diameter were more favorable for the early attachment and differentiation of osteoblasts on the surface of.titanium material.3. Effects of different diameters of TiO2nanotubes on ossteo-integration at the interface of implants and bone tissue:The model of dental implant in animial was constructed. The implants with different nanoscales were place in tibea of rabbits. Bone formation at implant interfaces was observed by biomechanical experiment, SEM, histochemical&immunohistochemical staining, hard tissue slices. The results showed that calcium phosphate deposition and bone formation weer more obvious in nanotube spicemens. Shear strength was higher in nanotube specimens than control group. Nanotubes with100nm diameter had the most obvious stimulation effect. It suggested that the modification of TiO2nanotubes on titanium implants demonstrated good biocompatibility and obviously promoted the integration at bone-implant interface.The present study successfully fabricated orderly, controllable size of TiO2nanotube on the surface of titanium implant material. This nanoscale topography modification affected osteoblastic function, promote tissue responses on implant-bone interfaces and lead rapid bone formation, which provided splendid prospect for application of TiO2nanotube in dental clinics. |
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