The effect of N-acetylcysteine on the antibacterial capability and biocompatibility of nano silver–containing orthodontic cement

Abstract

Objectives: To determine whether the incorporation of N-acetylcysteine (NAC) improves the antibacterial ability and biocompatibility of nano silver (NAg)–containing orthodontic cement. Materials and Methods: NAg was synthesized using a sodium citrate reduction method. NAg particles were characterized using transmission electron microscopy and ultraviolet-visible absorption spectra. NAg and NAC were incorporated into a resin-modified glass ionomer cement. Enamel shear bond strength (SBS), antibacterial capability, and cytotoxicity were evaluated. Results: Incorporating 0.15% NAg and 20% NAC had no adverse effect on the SBS of orthodontic cement (P . .1). Adding NAC into NAg-containing cement greatly reduced the biofilm metabolic activity and lactic acid production (P, .05) and lowered the colony unit–forming counts by approximately 1 log (P, .05). The cell viability against NAg-containing cement was improved by NAC (P, .05). Conclusions: The incorporation of NAC into NAg-containing cement achieved stronger antibacterial capability and better biocompatibility, without compromising the enamel SBS. The combined use of NAC and NAg is promising to combat caries in orthodontic practice. (Angle Orthod. 2021;91:515–521.)