Experimental Study Of Strontium-doped Brushite Coatings By Electrochemical Deposition

Background: Brushite has good biocompatibility, and has a faster degradation rateunder physiological conditions. At the same time, low doses of strontium canpromote bone formation, meanwhile inhibit bone resorption. In this study,strontium-doped brushite coatings titanium based were deposited by electrochemicaldeposition. We hope strontium and brushite can emerge a synergistic effect toenhance implant osseointegration efficiency, to provide a new idea for the expansionof implant denture indications and improving the success rate of dental implant.Materials and Methods:1. Strontium-doped brushite coatings on titanium platesurface were deposited by electrochemical deposition. The coating composition wasinvestigated by energy dispersive X-ray spectroscopy and X-ray diffraction. Thesurface morphologies of the coatings were studied through scanning electronmicroscopy.2. Strontium-doped brushite coatings on titanium implant surfacewere deposited by electrochemical deposition. The implants were implanted in tibiaproximal of SD rats. The osseointegration of implant with strontium-doped brushitecoatings in tibiae of rats was studied8weeks later after implant operation.3. A series extracted fluid were prepared from Strontium-doped brushite coatings ontitanium plate. The MC3T3-E1cells were cultured in the extract. Cell growth wasobserved. Cytotoxicity and proliferation were observed by MTT. Cell activity was detected by ALP. The expression of bFGF and VEGF mRNA were detected byRT-PCR.Results:1. Strontium-doped brushite coatings were deposited by electrochemicaldeposition successfully. The coating is mainly composed of different crystalcomposition, mostly composed of strontium hydrogen phosphate and brushite.2. By adjusting the different molar ratio of strontium and calcium, differentconcentrations of strontium doped brushite coating were obtained.3. Strontium and brushite cooperatively promoted the osseointegration of dentalimplants.4. Strontium doping with brushite coating increased implant osseointegration effect.10%strontium coating had a promoting effect.5. Strontium brushite coating promoted the expression of ALP in osteoblasts.6. Strontium brushite coating has good security and biocompatibility.7. Strontium brushite coating increased the expression level of bFGF and VEGFmRNA, thereby significantly enhanced the osteogenic differentiation.8.10%strontium coating has a promoting effect on the proliferation of osteoblasts.Conclusion: Experimental results showed that, the electrochemical deposition ofstrontium brushite coating can promote bone cell growth, promote implantosseointegration. This study lays a theoretical basis for the clinical application ofstrontium brushite coating implant and has certain value in clinical application.