Gold-oxoborate nanocomposite-coated orthodontic brackets gain antibacterial properties while remaining safe for eukaryotic cells

J Biomed Mater Res B Appl Biomater. 2023 May;111(5):996-1004. doi: 10.1002/jbm.b.35208. Epub 2022 Dec 3.

Abstract

The study's main objective is to limit bacterial biofilm formation on fixed orthodontic appliances. Bacterial biofilm formation on such devices (e.g., brackets) causes enamel demineralization, referred to as white spot lesions (WSL). WSL is significant health, social and economic problem. We provide a nanotechnology-based solution utilizing a nanocomposite of gold nanoparticles embedded in a polyoxoborate matrix (BOA: B-boron, O-oxygen, A-gold, Latin aurum). The nanocomposite is fully inorganic, and the coating protocol is straightforward, effective, and ecologically friendly (low waste and water-based). Prepared coatings are mechanically stable against brushing with a toothbrush (up to 100 min of brushing). Bacteria adhesion and antibacterial properties are tested against Streptococcus mutans-common bacteria in the oral cavity. BOA reduces the adhesion of bacteria by around 78%, that is, from around 7.99 × 105 ± 1.33 × 105 CFU per bracket to 1.69 × 105 ± 3.07 × 104 CFU per bracket of S. mutans detached from unmodified and modified brackets, respectively. Modified fixed orthodontic brackets remain safe for eukaryotic cells and meet ISO 10993-5:2009 requirements for medical devices. The gathered data show that BOA deposited on orthodontic appliances provides a viable preventive measure against bacteria colonization, which presents frequent and significant complications of orthodontic treatment.

Keywords: AuNP; Streptococcus mutans; adhesion; antibacterial; antimicrobials; dental appliances; inorganic nanocomposites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Adhesion
  • Eukaryotic Cells
  • Gold / pharmacology
  • Metal Nanoparticles*
  • Nanocomposites*
  • Orthodontic Brackets* / microbiology
  • Streptococcus mutans

Substances

  • Gold
  • Anti-Bacterial Agents