The Preparation Of Silver-loaded Nano Silica Coating And The Characterization Of Its Antimicrobial Activity And Biosafety

In the process of dental resin base material using, the surface of the denture iseasily for bacteria adhesion. The denture can influence the oral environment thatleads to a variation of oral flora, which increasing the incidence of denture stomatitis,tooth decay and periodontal disease. How to reduce the bacterial adhesion andimprove antibacterial properties of the denture base has become one of the hot topicsin the study of dental material science, but there still doesn’t have an ideal way tomeet this clinical need.The aim of this study is as follow. Firstly, synthesized a silver-loaded nanosilica antibacterial particle. The particles combined the stable silver nanoparticles andthe broad-spectrum antibacterial carrier with the mesoporous nano silica.Then mixed the synthesized antimicrobial with a kind of organic-inorganic hybridcoatings. Then put the coating curing on the surface of denture base resin, thusimprove the antibacterial properties of denture base.The synthesized of mesoporous nano silica microspheres used hexadecyltrimethyl ammonium bromide (CTAB) as template agent. The react was mixing theCTAB and other materials, then synthesized the mesoporous nano silica. Then soakedthe nano silica particles with silver nitrate, and changed the silver nitrate which wasadsorbed on the surface of microspheres into silver chloride. In this experiment, weprepared the mesoporous silica nano particles successfully. The size of particle wasabout300nm to400nm. The size and shape was relatively uniform, and there wasn’tobvious aggregation phenomenon. Then loaded the nanoparticles of silver chloride onthe surface or the channel of mesoporous silica nano particles,and produced thesilver-loaded nano silica antibacterial agent.This study tried to mix the polymer coating with the inorganic hybrid silicasol at a specific ratio. Then we obtained a kind of organic-inorganic hybrid coatingseventually. The mechanical performance of the hybrid coatings the hardness was over3H, the fracture resistance was remarkable, and the adhesive force was at level0~1 potential for clinical use.Using the tube dilution method to test Candida albicans and Streptococcusmutans’ minimum bactericidal concentration respectively. During the tested, one ofthe antibacterial properties of the sample was the best, the minimum bactericidalconcentration of Candida albicans was at0.312mg/ml while the minimumbactericidal concentration of Streptococcus mutans was at0.625mg/ml.While using the sticking membrane method to test the antibacterial propertiesof the hybrid coating which doped the sample at different proportion,the resultsshowed that the antibacterial effect of the coating was excellent, and could satisfiedthe clinical application needs. When the mass fraction of the sample was at2%, thecoating could kills more than99%of the bacterials. That means this sample belongsto the grade I of antimicrobial coating. And the coating not only has a stable color,but also doesn’t affect the color of denture base resin.This study tested the cytotoxicity of the silver-loaded nano silica coating usingMTT colorimetry. We detected the proliferation activity of L929cell that contactedwith extract liquid of antibacterial coatings for24hours. The result showed thematerials had a certain effect on promoting cell proliferation. When the dopedcontent of the antibacterial agent was at2%, the effect of promotes cell proliferationwas strongest. The coating, which the content of antibacterial agent was at2%, has anexcellent antibacterial effect and a high biological safety. It would have a broadprospect on dental clinical application.