title: Anti-biofilm dentin primer with quaternary ammonium and silver nanoparticles.
abstract: Antibacterial bonding agents could combat recurrent caries at the tooth-composite margins. The objectives of this study were to develop novel antibacterial dentin primers containing quaternary ammonium dimethacrylate (QADM) and nanoparticles of silver (NAg), and to investigate the effects on dentin bond strength and dental plaque microcosm biofilms for the first time. Scotchbond Multi-Purpose ("SBMP") bonding agent was used. QADM and NAg were incorporated into SBMP primer, yielding 4 primers: SBMP primer (control), control + 10% QADM (mass), control + 0.05% NAg, and control + 10% QADM + 0.05% NAg. Human saliva was collected to grow microcosm biofilms. The NAg particle size (mean ± SD; n = 100) was 2.7 ± 0.6 nm. Dentin shear bond strengths (n = 10) with human third molars were approximately 30 MPa for all groups (p > 0.1). QADM-NAg-containing primer increased the bacteria inhibition zone by 9-fold, compared with control primer (p < 0.05). QADM-NAg-containing primer reduced lactic acid production and colony-forming units of total micro-organisms, total streptococci, and mutans streptococci by an order of magnitude. In conclusion, novel QADM-NAg-containing primers were strongly antibacterial without compromising dentin bond strength, and hence are promising to inhibit biofilms and secondary caries. The processing method of incorporating QADM and NAg together into the same primer produced the strongest antibacterial effect, which could have a wide applicability to other bonding systems.
authors.affiliation: Biomaterials & Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland Dental School, Baltimore, MD 21201, USA.
authors.forename: L
authors.initials: L
authors.lastname: Cheng
authors.forename: K
authors.initials: K
authors.lastname: Zhang
authors.forename: M A S
authors.initials: MA
authors.lastname: Melo
authors.forename: M D
authors.initials: MD
authors.lastname: Weir
authors.forename: X
authors.initials: X
authors.lastname: Zhou
authors.forename: H H K
authors.initials: HH
authors.lastname: Xu
mesh_terms: D000704:Analysis of Variance; D018441:Biofilms / Q000187:drug effects*; D015169:Colony Count, Microbial; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003793:Dental Restoration, Permanent / Q000379:methods; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008964:Molar, Third; D053761:Nanocomposites / Q000737:chemistry; D000644:Quaternary Ammonium Compounds; D019279:Resin Cements; D033081:Shear Strength; D012834:Silver; D018709:Statistics, Nonparametric; D013295:Streptococcus mutans / Q000187:drug effects
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D000644:Quaternary Ammonium Compounds; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; D012834:Silver