title: Novel dental adhesive containing antibacterial agents and calcium phosphate nanoparticles.
abstract: Secondary caries remains the main reason for dental restoration failure. Replacement of failed restorations accounts for 50%-70% of all restorations performed. Antibacterial adhesives could inhibit biofilm acids at tooth-restoration margins, and calcium phosphate (CaP) ions could remineralize tooth lesions. The objectives of this study were to: (1) incorporate nanoparticles of silver (NAg), quaternary ammonium dimethacrylate (QADM), and nanoparticles of amorphous calcium phosphate (NACP) into bonding agent; and (2) investigate their effects on dentin bonding and microcosm biofilms. An experimental primer was made with pyromellitic glycerol dimethacrylate (PMGDM) and 2-hydroxyethyl methacrylate (HEMA). An adhesive was made with bisphenol-A-glycerolate dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA). NAg was incorporated into primer at 0.1 wt %. The adhesive contained 0.1% NAg and 10% QADM, and 0%-40% NACP. Incorporating NAg into primer and NAg-QADM-NACP into adhesive did not adversely affect dentin bond strength (p > 0.1). Scanning electron microscopy showed numerous resin tags, and transmission electron microscopy revealed NAg and NACP in dentinal tubules. Viability of human saliva microcosm biofilms on primer/adhesive/composite disks was substantially reduced via NAg and QADM. Metabolic activity, lactic acid, and colony-forming units of biofilms were much lower on the new bonding agents than control (p < 0.05). In conclusion, novel dental bonding agents containing NAg, QADM, and NACP were developed with the potential to kill residual bacteria in the tooth cavity and inhibit the invading bacteria along tooth-restoration margins, with NACP to remineralize tooth lesions. The novel method of combining antibacterial agents (NAg and QADM) with remineralizing agent (NACP) may have wide applicability to other adhesives for caries inhibition.
authors.affiliation: Biomaterials and Tissue Engineering Division, Department of Endodontics, Prosthodontics and Operative Dentistry, University of Maryland School of Dentistry, Baltimore, Maryland 21201, USA.
authors.forename: Mary Anne S
authors.initials: MA
authors.lastname: Melo
authors.forename: Lei
authors.initials: L
authors.lastname: Cheng
authors.forename: Michael D
authors.initials: MD
authors.lastname: Weir
authors.forename: Ru-Ching
authors.initials: RC
authors.lastname: Hsia
authors.forename: Lidiany K A
authors.initials: LK
authors.lastname: Rodrigues
authors.forename: Hockin H K
authors.initials: HH
authors.lastname: Xu
mesh_terms: D064751:Ammonium Compounds / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects*; D002130:Calcium Phosphates / Q000737:chemistry*; D002470:Cell Survival; D003731:Dental Caries / Q000517:prevention & control; D003738:Dental Cements / Q000737:chemistry*; D003804:Dentin / Q000737:chemistry; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D012463:Saliva / Q000382:microbiology*; D012834:Silver / Q000737:chemistry*; D013234:Stem Cells; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology
chemical_list: D064751:Ammonium Compounds; D000900:Anti-Bacterial Agents; D002130:Calcium Phosphates; D003738:Dental Cements; D008689:Methacrylates; D013778:Tetrazolium Salts; D013844:Thiazoles; D019344:Lactic Acid; D012834:Silver; C020243:calcium phosphate; C022616:thiazolyl blue