EDTA functionalized mesoporous silica (mSiO2-EDTA) for Ca2 + and Zn2+ rechargeable dental resin composites.

OBJECTIVE

The aim of this study was to (1) graft ethylenediamine tetraacetic acid (EDTA) onto mesoporous SiO2 (mSiO2) fillers to fabricate Ca2+ and Zn2+ rechargeable dental composites, (2) investigate the effect of EDTA modification on the properties of the composite resins.

METHODS

EDTA modified mSiO2 (mSiO2-EDTA) were prepared by a facile one-step silylating reaction. Ca2+ and Zn2+ were adsorbed onto mSiO2-EDTA via an ion solution immersing method to obtain mSiO2-EDTA-Ca and mSiO2-EDTA-Zn. The ion release behavior and recharge ability of the particles was investigated. Different mass fractions (5, 10, and 20 %) of the functional fillers were added into dental resins to investigate the ion release behavior of the composites. Dental composites containing 20 % fillers were selected to assess their ion recharge capacity, the remineralization potential of mSiO₂-EDTA-Ca loaded composites, and the antibacterial efficacy of those incorporating mSiO₂-EDTA-Zn. The effect of the fillers on the mechanical properties, light-curing performance, and biocompatibility of the dental composites was further evaluated.

RESULTS

mSiO2-EDTA were successfully synthesized, and Ca2+ and Zn2+ were adsorbed on the particles by the ion solution immersing method. The ions within the mSiO2-EDTA-Ca and mSiO2-EDTA-Zn particles as well as their corresponding dental composites could be released at acidic conditions, and fully recharged after releasing. Even after 10 release-recharge cycles, the ions in the dental resins could still be fully recharged by simply immersing the samples in ion solution for just 10 min. The continually released Ca2+ and Zn2+ exhibited corresponding functions as promoting mineralization or antibacterial activity. Furthermore, surface modification of mSiO2 with EDTA did not affect the mechanical properties, light curing performance, and biocompatibility of dental composites.

CONCLUSION

Novel dental composites with fully Ca2+ and Zn2+ recharge ability were obtained by surface functionalization of mSiO2 fillers with EDTA, which provided a potential way for the inhibition of secondary caries.