Effect of Black Seed (Nigella Sativa) Extract on Release of Some Minerals from Human Enamel: An in Vitro Study

Background: Black seed of Nigella sativa has been used for centuries to promote health due to its anti‑microbial, anti‑oxidant and anti‑inflammatory effects. This study was conducted to evaluate the ability of black seed water extract to reduce the release of potassium and zinc ions from enamel after acidic attack. Materials and Method: Twenty five maxillary human premolars were prepared and divided into five groups. The test solutions were included, black seed water extract in three concentrations (3%, 5% % and 7%), sodium fluoride (0.05%) as control positive and de‑ionized water as control negative. The teeth in each group were immersed separately in 40 ml of the test solution for two minutes, once daily and for twenty days. The teeth then prepared for subsequent etching and analysis by atomic flame spectrometer to measure the concentration of the released potassium and zinc ions. Result: The highest mean value of dissolved potassium ion was found in de‑ionized water group followed by 3% water extract of black seed while the lowest one was recorded in 7% black seed water extract. The statistical difference between the five groups was highly significant (p<0.01) by using ANOVA test. The highest mean value of dissolved zinc ion was found in de‑ionized water group followed by 0.05% sodium fluoride and 3% black seed extract while the lowest one was recorded in 7% water extract of black seed. The statistical difference between the five groups was also highly significant (p<0.01). Conclusion: Water extract of black seed has the ability to reduce the dissolution of potassium and zinc ions from the tooth and might increase tooth resistance against acid attack.