Evaluation of ion release and the recharge ability of glass-ionomer cement containing BioUnion filler using an in vitro saliva-drop setting assembly.

OBJECTIVE

A glass-ionomer cement (GIC) containing BioUnion filler has been reported to release Zn under acidic conditions and to inhibit oral bacteria on its surface. However, previous results are based on in vitro experiments under static conditions. This study aimed to assemble an in vitro saliva-drop setting to simulate in vivo conditions of the oral cavity and to investigate the ion releasing and recharging properties of the GIC containing BioUnion filler.

METHODS

The effective concentrations of Zn and F against Streptococcus mutans and saliva-derived multi-species biofilms were determined. Artificial saliva was dropped on the GIC containing BioUnion filler using the in vitro saliva-drop setting assembly and was periodically replaced with acetic acid. Ion release/recharge properties were investigated by measuring the release concentrations of Zn and F.

RESULTS

The concentration of Zn released from the BioUnion filler-containing GIC during seven days with repeated exposure to acid could be maintained at the level to inhibit S. mutans and saliva-derived multi-species biofilm formation. Moreover, the BioUnion filler-containing GIC could be recharged with Zn and F by the application of a tooth gel containing Zn and F. The release concentration of Zn after recharging was significantly higher than the effective concentration of Zn to hinder S. mutans and saliva-derived multi-species biofilm formation on material surfaces.

SIGNIFICANCE

The GIC containing BioUnion filler was shown to have the potential to inhibit biofilm formation in the oral cavity. In addition, recharging Zn and F would further enhance the effect of the GIC containing BioUnion filler.