title: An ORMOSIL-containing orthodontic acrylic resin with concomitant improvements in antimicrobial and fracture toughness properties.
abstract: Global increase in patients seeking orthodontic treatment creates a demand for the use of acrylic resins in removable appliances and retainers. Orthodontic removable appliance wearers have a higher risk of oral infections that are caused by the formation of bacterial and fungal biofilms on the appliance surface. Here, we present the synthetic route for an antibacterial and antifungal organically-modified silicate (ORMOSIL) that has multiple methacryloloxy functionalities attached to a siloxane backbone (quaternary ammonium methacryloxy silicate, or QAMS). By dissolving the water-insoluble, rubbery ORMOSIL in methyl methacrylate, QAMS may be copolymerized with polymethyl methacrylate, and covalently incorporated in the pressure-processed acrylic resin. The latter demonstrated a predominantly contact-killing effect on Streptococcus mutans ATCC 36558 and Actinomyces naselundii ATCC 12104 biofilms, while inhibiting adhesion of Candida albicans ATCC 90028 on the acrylic surface. Apart from its favorable antimicrobial activities, QAMS-containing acrylic resins exhibited decreased water wettability and improved toughness, without adversely affecting the flexural strength and modulus, water sorption and solubility, when compared with QAMS-free acrylic resin. The covalently bound, antimicrobial orthodontic acrylic resin with improved toughness represents advancement over other experimental antimicrobial acrylic resin formulations, in its potential to simultaneously prevent oral infections during appliance wear, and improve the fracture resistance of those 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: Jeevani
authors.initials: J
authors.lastname: Epasinghe
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Rueggeberg
authors.forename: Li-na
authors.initials: LN
authors.lastname: Niu
authors.forename: Donald
authors.initials: D
authors.lastname: Mettenberg
authors.forename: Cynthia K Y
authors.initials: CK
authors.lastname: Yiu
authors.forename: John D
authors.initials: JD
authors.lastname: Blizzard
authors.forename: Christine D
authors.initials: CD
authors.lastname: Wu
authors.forename: Jing
authors.initials: J
authors.lastname: Mao
authors.forename: Connie L
authors.initials: CL
authors.lastname: Drisko
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*; D000190:Actinomyces / Q000254:growth & development*; D000890:Anti-Infective Agents / Q000737:chemistry*; D002176:Candida albicans / Q000254:growth & development*; D009968:Orthodontic Appliances, Removable / Q000382:microbiology; D012117:Resins, Synthetic / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D013295:Streptococcus mutans / Q000254:growth & development*
chemical_list: D000180:Acrylic Resins; D000890:Anti-Infective Agents; D012117:Resins, Synthetic; D012833:Siloxanes; C510784:ormosil