evaluating the protective effect of a nano-emulsion containing propolis and nigella sativa nano-particles on enamel surface

Background: due to the lack of data, the current study aims to determine the protective effect of a nanoemulsion containing nigella sativa (ns) and propolis extract (comparing the macroscale and nanoscale form) on the mineral content of enamel after tooth brushing. methods: in this experimental study, six human premolars were sectioned buccolingually, and the specimens were randomly divided into four groups. these groups were treated with nanoemulsion alone, nanoemulsion accompanied by propolis in either bulk or nanoparticle form, and distilled water (as a control). the treatment procedure was seven consecutive days, in which the specimens were etched and brushed daily. the ca and p content of the enamel surface was quantified by scanning electron microscopy with energy dispersive x-ray spectroscopy (sem/edx), and the surface roughness was recorded by a profilometer. moreover, the sem micrographs of the specimens were captured. ultimately, the data were analyzed using one-way anova with lsd post hoc analysis (α=0.05). results: the ca and p content of the groups were significantly different (p=0.000 and p=0.000), but the difference in the surface roughness of the experimental groups was not significant (0.27). conclusion: the beneficial effect of ns+propolis as a barrier on tooth surface was confirmed. however, its effect on the mineral content of enamel needs further assessment.