SEM Investigation at Microstructure Level and Recovering Process of Cortical Bone Used for Dental Implants

摘要

An important issue for the restorative dentistry is the restoration of the missing structure for damaged or destroyed tooth. A large variety of treatments and advanced biomaterials are used, especially in direct implants where defects of human skeleton may occur. The biomaterials behavior related to a specific human skeleton (at cortical bone level) is the most important aspect in the restorative dentistry. A deep investigation referring to morphology and composition behavior of the biomaterials used for bone recovering in dental surgery is requested. At the structural level, the bones are composed of inorganic and organic compounds and water, actually being considered a composite biomaterial, each component contributing to the bone remarkable mechanic properties. Our study presented in this paper aims to highlight the morphological and compositional changes that occur in human bone structure during the preparation of bulk samples and biomaterial resumption during osteogenesis process for subsequent analysis by X-ray fluorescence spectrometry (XRF), atomic absorption, scanning electron microscopy and EDS methods. We applied a method for hard tissue (cortical bone) processing by thermal treatment, in order to obtain homogenous particles (concerning both their shape and size) having elemental compositions as close as possible to the "real" physiological values. This homogeneous material will be used for in vitro XRF analyses, in order to avoid the artifacts induced by the in situ matrix effect. By heat treatment, below 300 deg C, the Ca/P stoichiometric ratio was maintained between 1.65 and 1.69 for all investigated samples. Above this temperature, the Ca/P ratio decreased below its physiological value. Using scanning electron microscopy techniques we characterized the morphological changes occurring during samples heat processing and bone recovering stages using dental additional biomaterials.