Evaluation of the Effectiveness of Azadirachta Indica Leaves Against Tooth Decay Microbes in Kirkuk City

Abstract

100 samples were collected from people suffering from tooth decay attending dental clinics in Kirkuk City. The results showed that 59(59%) of samples have positive growth on Mannitol salt agar, MacConkey agar, and blood agar. While the remaining samples had no growth. Isolates were identified using biochemical and microscopic tests, 20 samples of Streptococcus mutans bacteria were isolated, with the highest percentage reaching (33.9%), 16 Staphylococcus aureus isolates representing (27.1%), followed by 13 (22%) Candida albicans isolates and 10 (17%) Staphylococcus epidermidis isolates. Aqueous and alcoholic extracts of the neem plant were prepared, the aqueous extract showed higher activity against the isolates than the alcoholic extract. Neem extracts also showed higher effectiveness against bacteria compared to fungi, Ciprofloxacin was used as a control agent for bacteria and fluconazole for fungi. Streptococcus mutans recorded the highest inhibition zone of 4.5±0.53 and 2.3±0.51 at 100 mg/mL concentrations for aqueous and alcoholic extracts, respectively, followed by the rest of the isolates with different inhibition zones. The minimum inhibitory concentration for the aqueous extract of neem was (40 mg/ml) and (60 mg/ml) for the alcoholic extract, While C. albicans recorded (20 mg/ml) and (40 mg/ml) for the aqueous and alcoholic extracts, respectively. Keywords: dental caries, neem plant, bacteria, fungi.