IRCT20201218049748N1 IRCT 2021-08-05 Tehran University of Medical Sciences Efficiency of different brushing methods Comparison of the effectiveness of different brushing methods with the usual method in removing microbial plaque in 11th and 12th grade students. 2021-09-22 anticipated 72 Complete https://irct.ir/trial/53171 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Not used, Assignment: Parallel, Purpose: Education/Guidance, Randomization description: Simple randomization with block design. Individual randomization unit . randomization tool also sealed envelopes, Blinding description: Participants will be blind from the goals of the study and the name of the brushing methods. Data collectors will be blind from the goals of the study. The whole study process and the existence of parallel groups will be explained to the participants. 2 Efficiency of different brushing methods compared to the usual method of each person .. Intervention 1: Control group: Initially,all volunteers will not brush their teeth for next 48 hours. Then they will brush with their usual brushing method twice a day and the plaque index and gingival index will record. Intervention 2: . Intervention 3: Intervention group : Do not brushing for next 48 hours. Plaque index and gingival index will be recorded. then they will brush twice in 24 hours using Modified Bass method. and after that, plaque index and gingival index will record. No - There is not a plan to make this available Justification or reason for not sharing IPD is There is no information