Abstract: Objective: To study the changes of oral health indexes in adolescent orthodontic patients under different brushing time, and to provide basis for the orthodontists to give effective dental health promotion in clinic. Methods: A total of 123 adolescent orthodontic patients were included, and they were divided into 1-3min, 3-5 min, 5-7 min and 7-10 min groups based on the brushing time recorded in the period of orthodontic treatment. The relationship between different brushing time and oral health indexes was evaluated 1,3,and 6 months after experiment, such as sulcus bleeding index(SBI),plaque index(PLI), debris index-simplified(DI-S) and enamel demineralization index(EDI). Results: Compared with 1-3 min and 3-5 min groups, the SBI, PLI, and DI-S of the patients in 5-7 min group were significantly reduced(P<0.05). There was no significant differences of SBI, PLI, DI-S, and EDI between 5-7 min group and 7-10 min group (P>0.05). Conclusion: Brushing teeth more than 5 min can improve the oral hygiene significantly and the best time is 5-7 min;the orthodontists should require the patients to brush teeth at least for 5 min.

Key words: sulcus bleeding index, brushing time, oral hygiene, plaque index, debris index-simplified, enamel demineralization index, orthodontics