title: Incorporation of silver nanoparticles on the surface of orthodontic microimplants to achieve antimicrobial properties.
abstract: OBJECTIVE
  Microbial aggregation around dental implants can lead to loss/loosening of the implants. This study was aimed at surface treating titanium microimplants with silver nanoparticles (AgNPs) to achieve antibacterial properties.
  
  
  METHODS
  AgNP-modified titanium microimplants (Ti-nAg) were prepared using two methods. The first method involved coating the microimplants with regular AgNPs (Ti-AgNP) and the second involved coating them with a AgNP-coated biopolymer (Ti-BP-AgNP). The topologies, microstructures, and chemical compositions of the surfaces of the Ti-nAg were characterized by scanning electron microscopy (SEM) equipped with energy-dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). Disk diffusion tests usingStreptococcus mutans,Streptococcus sanguinis, andAggregatibacter actinomycetemcomitanswere performed to test the antibacterial activity of the Ti-nAg microimplants.
  
  
  RESULTS
  SEM revealed that only a meager amount of AgNPs was sparsely deposited on the Ti-AgNP surface with the first method, while a layer of AgNP-coated biopolymer extended along the Ti-BP-AgNP surface in the second method. The diameters of the coated nanoparticles were in the range of 10 to 30 nm. EDS revealed 1.05 atomic % of Ag on the surface of the Ti-AgNP and an astounding 21.2 atomic % on the surface of the Ti-BP-AgNP. XPS confirmed the metallic state of silver on the Ti-BP-AgNP surface. After 24 hours of incubation, clear zones of inhibition were seen around the Ti-BP-AgNP microimplants in all three test bacterial culture plates, whereas no antibacterial effect was observed with the Ti-AgNP microimplants.
  
  
  CONCLUSIONS
  Titanium microimplants modified with Ti-BP-AgNP exhibit excellent antibacterial properties, making them a promising implantable biomaterial.
authors.affiliation: Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Korea.
authors.forename: Adith
authors.initials: A
authors.lastname: Venugopal
authors.affiliation: Department of Chemistry Education, Kyungpook National University, Daegu, Korea.
authors.forename: Nallal
authors.initials: N
authors.lastname: Muthuchamy
authors.affiliation: Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Korea.
authors.forename: Harsh
authors.initials: H
authors.lastname: Tejani
authors.affiliation: Research Institute of Advanced Energy Technology, Kyungpook National University, Daegu, Korea.; Department of Nanoscience and Nanotechnology, Kyungpook National University, Daegu, Korea.
authors.forename: Anantha-Iyengar
authors.initials: AI
authors.lastname: Gopalan
authors.affiliation: Department of Chemistry Education, Kyungpook National University, Daegu, Korea.; Research Institute of Advanced Energy Technology, Kyungpook National University, Daegu, Korea.; Department of Nanoscience and Nanotechnology, Kyungpook National University, Daegu, Korea.
authors.forename: Kwang-Pill
authors.initials: KP
authors.lastname: Lee
authors.affiliation: Department of Oral Microbiology and Immunology, Kyungpook National University, Daegu, Korea.
authors.forename: Heon-Jin
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Korea.
authors.forename: Hee Moon
authors.initials: HM
authors.lastname: Kyung
keywords: Antimicrobial; Microimplant; Nanosilver