Green Synthesis of nano calcium oxide using Olive plant extracts and studying its effect on bacteria causing dental caries in children

One hundred clinical samples were collected from children suffering from oral diseases such as tooth decay and root canal inflammation under the supervision of a specialist dentist, using sterile cotton swabs from the site of infection, for patients visiting specialized dental centers in Baiji city, Salah al-Din Governorate. Their ages ranged from 3 to 13 years, and for the period from the beginning of September 2023 until February, where 100 pathogenic bacterial isolates were isolated from clinical samples, diagnosed based on cultural and microscopic characteristics, in addition to diagnosis with the Vitek2 device for diagnosis at the species level. The genus Streptococcus mutans appeared in it at a rate of 18.18%, which is the most significant percentage among other genera. The following species were obtained: Staph. Aureus, Staph.epidermis, Staph.saprophyticus, Micro.luteus, and B.subtilius. The sensitivity of bacterial isolates to antibiotics was tested, and the results showed that they had the highest resistance to cefepime and the least resistance to Gentamycin. Olive leaves were collected and characterized, the aqueous extract was prepared, and its acidity was estimated. The antimicrobial activity was tested using the disk diffusion method. The study showed that the aqueous extract of olive leaves had inhibitory activity against Staphylococcus aureus bacteria with an inhibition diameter of 23 mm. The bio-manufacturing of nano calcium oxide from olive leaf extract was also carried out, and its inhibitory activity on some bacterial isolates was studied. The results showed that the nano solution has activity against the bacterial genus Staphylococcus aureus. In this study, the anti-oxidative activity (ROS%) of the aqueous extract of fig and olive leaves was determined, as olive plants demonstrated more muscular anti-oxidative activity compared to figs, as well as ascorbic acid, which served as a positive control in this experiment.