Nanomodification of mineral trioxide aggregate for enhanced physiochemical properties

摘要

Aim To analyse the physicochemical properties of a Nano white mineral trioxide aggregate (NWMTA) and compare it with white mineral trioxide aggregate (WMTA). Methodology White mineral trioxide aggregate and NWMTA were prepared and mixed according to the manufacturer's instructions. Surface area of powder before hydration, setting time, X-ray diffraction and microhardness at pH values of 4.4 and 7.4 were evaluated by Brunauer-Emmett-Teller, ISO Specification no.6876, Vickers microhardness, and energy-dispersive X-ray spectroscopy equipped with X-ray colour (dot) map for both cements. anova and Mann-Whitney were used for statistical analysis at a significance level of 0.5. Results The mean±SD of surface area and setting time were 1.8 ± 0.2 m 2 g -1 and 43±2min for WMTA and 7.8±1.2m 2g -1 and 6±1min for NWMTA, respectively. Mean±SD of Microhardness were 16± 2, 51 ±1, 69±1 and 81±2 for WMTA at pH values of 4.4 and 7.4 and for NWMTA correspondingly. Numbers of open porosity over the surface were 88± 24 and 44±13 for WMTA and NWMTA, respectively. Statistical tests revealed significant differences between the groups (P0.001) in surface area, setting time and surface hardness for both cements. Uniform distribution of strontium was only observed in NWMTA. However, other compounds were not significantly different. Conclusion Increasing surface area of powder can reduce setting time and increase microhardness even at lower pH values after hydration.