The effect of Green tea, Chlorhexidine and green coffee extract on salivary Streptococcus mutans

INTERVENTION: Intervention 1: Intervention group:Green tea methanolic extract 20%, for 30 minutes and 1 week after saliva taking from 4 to 6 year old children, 1 cc gel with a syringe and a cotton swab is applied to all teeth of the child. Intervention 2: Intervention group: Green coffee 10% , for 30 minutes and 1 week after saliva taking from 4 to 6 year old children, 1 cc gel with a syringe and a cotton swab is applied to all teeth of the child. Intervention 3: Control group: Chlorhexidine 0.2% , 30 minutes and 1 week after saliva taking from 4 to 6 year old children, 1 cc gel with a syringe and a cotton swab is applied to all teeth of the child. CONDITION: Streptococcus mutans. ; ??????? ?????? PRIMARY OUTCOME: Streptococcus mutans. Timepoint: 30 minutes and 1 week later application of interventions. Method of measurement: PCR. INCLUSION CRITERIA: Preschoolers aged 4 to 6 years