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

Abstract

To determine whether the incorporation of N-acetylcysteine (NAC) improves the antibacterial ability and biocompatibility of nano silver (NAg)-containing orthodontic cement. 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. 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). 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.