title: Effect of water-aging on the antimicrobial activities of an ORMOSIL-containing orthodontic acrylic resin.
abstract: Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol-gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly(methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances.
authors.affiliation: Department of Stomatology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Shi-Qiang
authors.initials: SQ
authors.lastname: Gong
authors.forename: D Jeevanie
authors.initials: DJ
authors.lastname: Epasinghe
authors.forename: Bin
authors.initials: B
authors.lastname: Zhou
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Niu
authors.forename: Kirk A
authors.initials: KA
authors.lastname: Kimmerling
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Rueggeberg
authors.forename: Cynthia K Y
authors.initials: CK
authors.lastname: Yiu
authors.forename: Jing
authors.initials: J
authors.lastname: Mao
authors.forename: David H
authors.initials: DH
authors.lastname: Pashley
authors.forename: Franklin R
authors.initials: FR
authors.lastname: Tay
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology*; D018407:Bacterial Physiological Phenomena / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004355:Drug Stability; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000494:pharmacology*; D012833:Siloxanes / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D000890:Anti-Infective Agents; D000644:Quaternary Ammonium Compounds; D012833:Siloxanes; C510784:ormosil; D014867:Water