Effect of enamel matrix proteins on the growth of apatite coating on dual thermo-etching modified titanium / 中国组织工程研究

ABSTRACT

BACKGROUND:Various surface modification techniques have been used to improve the bioactivity of titaniumimplant in vivo. OBJECTIVE:To investigate the effects of enamel matrix proteins (EMPs) on the growth of apatite coatings on dual thermo-etching treated pure titanium. METHODS:EMPs were extracted from porcine tooth germs and then were identified. Dual thermo-etching was applied to treat titanium samples fol owing polished, and then immersed in a blank simulated body fluid supersaturated calcification solution (control group) or supersaturated calcification solution containing different concentrations of EMPs for 7 days. The morphology of samples was observed using scanning electron microscope, and element components and crystal structures of the apatite coatings were analyzed by energy dispersive spectrometer and X-ray diffraction. RESULTS AND METHODS:After double-etching, a pit-like rough surface was observed on the titanium plate. After 7-day mineralization, in the control group, no overt calcium-phosphate deposits were found on the titanium surface;however, in the experimental groups, there were calcium-phosphate deposits, whose quantity and morphology changed with increasing concentrations. Energy dispersive spectrometer showed that the main element components of the mineralized coating included calcium, phosphorus, oxygen and carbon, and the calcium-phosphate ratio ranged from 1.32 to 1.41. The apatite coatings were proved to be carbonate hydroxyapatite by X-ray diffraction. To conclude, EMPs promote apatited deposition on pure titanium surfaces in a concentration-dependent manner.