title: Antibacterial silver-containing silica glass prepared by sol-gel method.
abstract: Recently, various inorganic antibacterial materials containing silver have been developed and some of them are in commercial use. Colorless and more chemically durable materials which slowly release the silver ion for a long period are, however, desirable to be developed for medical applications such as composite resin for dental restoration. In the present study, Si(OC2H5)4, Al(NO3)3 x 9H2O, AgNO3, HNO3, C2H5OH and H2O solutions with various Al/Ag atomic ratios under a constant Si/Ag atomic ratio of 1/0.023 were kept at 40 degrees C for gelation and drying. Thus obtained gels were pulverized into fine powders with average particle size of approximately 10 microm and then heat-treated at 900-1000 degrees C for 2 h. For the composition Al/Ag = 0, a yellow-colored glass was formed, since the silver existed in the form of metallic colloids in the glass. However, for the compositions Al/Ag > or = 1, colorless glasses were successfully obtained, since the silver existed in the form of Ag+ ions in the glasses. For the composition Al/Ag = 0, the silver ions got released rapidly into the water, whereas, for the compositions Al/Ag > or = 1, they gradually got released into the water at a controlled rate. A composite of the obtained powders with Al/Ag atomic ratio of 1 with Bis-GMA/TEGDMA in 70:30 weight ratio showed excellent antibacterial property. The sol-gel derived silica glass powders containing silver with compositions Al/Ag > or = 1 are believed to be useful as an antibacterial material for medical applications such as filler of composite resin for dental restoration.
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kawashita
authors.forename: S
authors.initials: S
authors.lastname: Tsuneyama
authors.forename: F
authors.initials: F
authors.lastname: Miyaji
authors.forename: T
authors.initials: T
authors.lastname: Kokubo
authors.forename: H
authors.initials: H
authors.lastname: Kozuka
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D005782:Gels; D005898:Glass / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D009566:Nitrates / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011208:Powders; D012821:Silanes / Q000737:chemistry*; D012835:Silver Nitrate / Q000737:chemistry* / Q000494:pharmacology*; D013056:Spectrophotometry, Ultraviolet; D013295:Streptococcus mutans / Q000187:drug effects; D014961:X-Ray Diffraction
chemical_list: D017607:Aluminum Compounds; D000900:Anti-Bacterial Agents; D003188:Composite Resins; D005782:Gels; D009566:Nitrates; D011109:Polymethacrylic Acids; D011208:Powders; D012821:Silanes; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C040733:tetraethoxysilane; D017438:Bisphenol A-Glycidyl Methacrylate; D012835:Silver Nitrate; C050609:aluminum nitrate