Objective: The aim of this study is to ascertain if a ZnO and a ZnCl2-doped resin are bioactive materials, inducing calcium (Ca) and phosphate deposition (P).
Method: Bioactivity was quantified trough a simulated body fluid solution (SBFS) immersion test (Kokubo). 36 resin disks were prepared with the following materials: 1) Single Bond -3M/ESPE-, 2) Single Bond + ZnO particles 20%wt and 3) Single Bond + ZnCl22%wt; specimens were polymerized, polished and stored in SBFS up to 21 days. At time 0, 24 h, 7 d and 21 d surfaces were analyzed trough stereomicroscope, confocal laser Raman, high resolution scanning electron microscope (HRSEM) and energy-dispersive analysis (EDX) for morphological and chemical composition.
Result: Under the stereomicroscope, crystal formations were encountered in both zinc-doped resin adhesives, after 7 days of immersion. It was detected, by EDX, that the ZnO-filled resin produced Zn, Ca and P deposition (globular formations were observed by HRSEM). Hydroxyapatite, scholzite and hopeite formation were encountered by Raman spectra analysis. Zn and P clusters deposition was detected by HRSEM and EDX in the experimental ZnCl2-doped resin, hopeite formation was identified by Raman. Single Bond did not produce mineral precipitation.
Conclusion: ZnO-doped resin is bioactive and may induce remineralization of hard tissues. ZnCl2-resin may exert bioactivity, but trough the previously described process of hopeite conversion into apatite after SBFS immersion.
CICYT/FEDER MAT2011-24551, JA-P08-CTS-3944.