title: Composite resin reinforced with silver nanoparticles-laden hydroxyapatite nanowires for dental application.
abstract: The object is to find a functional one-dimensional nanofibrous filler for composite resin, which is able to provide both efficient reinforcement and high antibacterial activity.
  
  
  
  Hydroxyapatite (HA) nanowires were synthesized via hydrothermal technique using calcium oleate as the precursor. Polydopamine (PDA)-coated HA (HA-PDA) nanowires were prepared by soaking HA nanowires in dopamine (DA) aqueous solution. Silver nanoparticles (AgNPs)-laden HA (HA-PDA-Ag) nanowires were prepared via reduction reaction by adding silver nitrate and glucose into HA-PDA suspensions in DI water. The resulted HA-PDA-Ag nanowires were then mixed into Bis-GMA/TEGDMA (50/50, w/w) at 4-10wt.%, thermal-cured, and submitted to characterizations including mechanical properties, interfacial adhesion between filler and resin matrix, distribution of HA nanowires and AgNPs, as well as silver ion release, cytotoxicity and antibacterial activity.
  
  
  
  HA-PDA-Ag nanowires were readily obtained and the loading amounts of AgNPs could be controlled by adjusting the feeding doses of silver nitrate and HA-PDA nanowires. Benefiting from the PDA surface layer, HA-PDA-Ag nanowires could disperse well in composite resin and form good interfacial adhesion with the resin matrix. In comparison with neat resin, significant increases in flexural strength and modulus of cured composites were achieved at the addition amounts of HA-PDA-Ag nanowires being 6-8wt.%. The distribution of AgNPs was homogeneous throughout the resin matrix in all designs, which endowed the composites with high antibacterial activity against streptococcus mutans. Continuous silver ion release from composites was detected, however, it was determined the composites would have insignificant cytotoxicity based on the proliferation of L929 fibroblasts in extracts of HA-PDA-Ag nanowires.
  
  
  
  The finding proved that HA-PDA-Ag nanowires could serve as functional nanofillers for composite resins, which should help much in developing materials for satisfactory long-term clinical restorations.
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, PR China.
authors.forename: Miao
authors.initials: M
authors.lastname: Ai
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, PR China.
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Du
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, PR China.
authors.forename: Siqi
authors.initials: S
authors.lastname: Zhu
authors.affiliation: School and Hospital of Stomatology, Tianjin Medical University, Tianjin 300070, PR China.
authors.forename: Hongjuan
authors.initials: H
authors.lastname: Geng
authors.affiliation: School and Hospital of Stomatology, Tianjin Medical University, Tianjin 300070, PR China.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, PR China. Electronic address: caiqing@mail.buct.edu.cn.
authors.forename: Qing
authors.initials: Q
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, PR China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Yang
mesh_terms: D003188:Composite Resins; D017886:Durapatite; D006801:Humans; D008422:Materials Testing; D053768:Metal Nanoparticles; D053770:Nanowires; D012834:Silver
chemical_list: D003188:Composite Resins; D012834:Silver; D017886:Durapatite
keywords: Antibacterial; Composite resin; Hydroxyapatite nanowires; Silver nanoparticles; cytotoxicity