Clinical evaluation of the effect of fluoride–releasing elastomeric chains on the number of Streptococcus mutans in orthodontic patients

INTERVENTION: control group: conventional elastomeric chains used Intervention 1: study group: fluoride releasing elastomeric chains would used. Intervention 2: control group: conventional elastomeric chains used. Prevention study group: fluoride releasing elastomeric chains would used CONDITION: Dental caries. ; Other specified symptoms and signs involving the digestive system and abdomen Other specified symptoms and signs involving the digestive system and abdomen PRIMARY OUTCOME: Streptpcpccus mutans bacteria. Timepoint: on days 0; 7; 14; 28. Method of measurement: counting number of Streptococcus mutans colonies. INCLUSION CRITERIA: The inclusion criteria are:18‐28 years old? teeth with normal size? are in overall health situation? do not used antibiotics within the previous 2 weeks. Exclusion criteria: lake of above criteria