Osteogenic And Long-term Antibacterial Property Of Sr/Ag-doped Micropore Coating On Titanium Implants In Vivo

Objective Micro-arc oxidation technique(MAO)was used to prepared strontium(Sr)and silver(Ag)-doped screw-type implant with ideal physicochemical and biological properties under different reaction volt and time.Animal studies were also performed to confirm the osteogenic and antibacterial properties of Sr/Ag-dopped micropore coating in vivo.The results of this study will provide valuable experimental data for application of Sr/Ag-doped titanium implants in dental clinics.Methods 1 MAO were performed at 250 V,300V and 350 V for 10 min,and at 250 V for 10 min,15min and 20 min,respectively,to prepare Sr/Ag-doped micropore coatings on screw-type titanium implants.Scanning electron microscope,X-ray energy spectroscopy,hydrophilicity analysis,and cell adhesion experiments were used to analyze the micromorphology,element distribution,hydrophilicity,and cytocompaitibility of implant coatings and to determine the ideal reaction voltage and the reaction time.2 Implants in group M(MAO group),M-Sr group(MAO+strontium-doped group)and M-Sr/Ag group(MAO+strontium/silver-doped group)were inserted into the tibiae of rats.X-ray examination,remove torque test,bone fluorescent labeling observation and bone histological analysis were applied to confirm the osteogenic property of the Sr/Ag-doped micropore coatings.Three months after implantation,staphylococcus aureus were seeded around implant neck,inflammatory reaction and bone destruction around the implant were observed by general observation,X-ray examination and histological observation,to evaluate the long-term antibacterial property of the Sr/Ag-doped micropore implants.Results 1 When MAO were performed under the condition at 250 V for 15 min,Sr/Agdoped coating,with uniformly distributed and similar sized micropores at both peak and bottom of threads,could be prepared on screw-type implants and the coating exhibited both good hydrophilicity and cytocompaitibility.2 In vivo animal studies showed that the implants with M-Sr/Ag coating promoted peri-implant new bone formation,increased implant-bone contact and removal torque,exhibited excellent osteogenic property,although the osteogenic effect was slightly weaker than implants with Sr-doped coating,probably due to the weak toxic action of Ag within the coating.Furthermore,no bacteria-induced infection and bone destruction were observed around the implants with Sr/Ag-doped coating and the coating exhibited excellent long-term antibacterial property against bacteria-induced periimplantitis.Conclusion 1 When micro-arc oxidation is performed at 250 V for 15 min,Sr/Ag-doped micropore coating can be prepared on screw-type implants and the implants show both good physicochemical properties and biological properties.2 The Sr/Ag-doped micropore coating implants have both good osteogenic and long-term antibacterial properties in vivo,can promote implant osseointegration and effectively prevent bacteria-induced peri-implantitis,and therefore show good prospect for its application in dental clinics.Figure 25;Table 6;References 108...