Antibacterial effects and physical properties of a glass ionomer cement containing BioUnion filler with acidity-induced ability to release zinc ion

Abstract

BioUnion filler is a bioactive glass particle that releases Zn 2+ in an acidic environment. In this study, the ion release, antibacterial, and physical properties of a glass ionomer cement (GIC) incorporating BioUnion filler (CA) were assessed in vitro. The concentration of Zn 2+ released from CA into acetic acid was higher than that released into water and its minimum inhibitory concentrations against six oral bacterial species. Moreover, the concentration of Zn 2+ -release was maintained during all the seven times it was exposed to acetic acid. Compared to a conventional cement and resin composite, CA significantly inhibited the growth of oral bacteria and hindered their adhesion on the material surface. Thus, our study outcomes show that the release of Zn 2+ from CA in the acidic environment does not affect its compressive strength.

Establishment of novel in vitro culture system with the ability to reproduce oral biofilm formation on dental materials

“…Contrarily, no significant difference in the number of bacterial cells in the biofilm and the volume of the biofilm was found between conventional fluoride-releasing GIC and resin composites. Therefore, the results obtained in this study were comparable to those previously reported by simple in vitro testing demonstrating that BioUnion filler-containing GICs inhibit the growth and adherence of oral bacteria more effectively than conventional fluoride-releasing GICs 41 , 42 . Based on these findings, the in vitro culture system established in the present study is suitable for evaluating the efficacy of restorative materials with antibacterial and anti-biofilm effects.…”

“…The GIC containing BioUnion filler for root surface restoration (Caredyne ® Restore) is currently in the market. The closed-system biofilm model (i.e., incubation under static conditions) was used to demonstrate that acidity-induced release of Zn 2+ from the GIC containing BioUnion filler effectively inhibited the growth and adherence of Streptococcus mutans , S. sobrinus, S. oralis, S. mitis , Actinomyces naeslundii , and Fusobacterium nucleatum 41 . Previously, we developed a saliva-drop setting assembly that can flow AS at 32 mL/h and drop acetate buffer solution (pH 4.5) three times per day to simulate in vivo conditions of the oral cavity, to investigate the ion releasing properties of BioUnion filler-containing and conventional fluoride-releasing GICs 42 .…”

“…Results of this study revealed that GIC containing BioUnion filler reduced the volume of biofilm formed as well as the number of bacteria in the biofilm. It has been reported that the pH values of several oral bacterial species (i.e., S. mutans , S. sobrinus , S. oralis , S. mitis , A. naeslundii , and F. nucleatum ) related to dental plaque formation decreased (4.2–4.7) when they were cultured under sucrose-supplemented media 41 , 43 , 44 . Sucrose also increases the porosity of the biofilm, allowing carbohydrates to diffuse into the deepest parts of the biofilm, which results in low plaque pH values due to microbial catabolism 17 .…”

Fabrication of pH-Responsive Zn2+-Releasing Glass Particles for Smart Antibacterial Restoratives

“…Zinc is one of these ions known to inhibit oral bacteria. Liu et al reported that the release of Zn 2+ from the BioUnion filler, a glass powder composed of silicon dioxide (SiO 2 ), zinc oxide (ZnO), calcium oxide (CaO), and fluorine (F), accelerated under acidic conditions at a pH of 4.5 [ 15 , 16 , 17 ]. Thus, such technology enables the on-demand release of antimicrobial components from restorative materials.…”

“…Thus, such technology enables the on-demand release of antimicrobial components from restorative materials. Liu et al also reported that the acidity-induced release of Zn 2+ from the glass ionomer cement (GIC) containing BioUnion filler (Caredyne ® Restore, GC Corp., Tokyo, Japan) effectively inhibited the growth and adherence of acidogenic bacteria [ 17 ].…”