RESUMEN
Objective:To investigate the effects of bracketless invisible appliance(BI),self-ligating bracket(SB) and conventional brackets(CB) on periodontal indices(PI) and inflammatory cytokine levels in gingival crevicular fluid(GCF) in adult orthodontic patients.Methods:90 orthodontic patients were randomly divided into CB,SB and BI groups(n =30).The subjects in the 3 groups accepted invisalign,Demon Q self-ligating brackets and conventional MBT brackets respectively.Plaque index(PLI),probing depth (PD) and interleukin-13 (IL-3),tumor necrosis factor-α (TNF-a) in GCF were analyzed before treatment,l,3 and 6 months after treatment,and after appliance removed respectively.Results:1 to 6 months after treatment,PI,IL-β and TNF-α rose constantly in CB and SB groups and reached to their top 6 months after treatment.There were no statistical differences between CB and SB groups 1 months after treatment,while PI,IL-β and TNF-α of SB group were lower than those of CB group 3 and 6 months after treatment and after therapy completed.PLI、IL-1 β and TNF-α of BI group were significantly increased 6 months after treatment.However,each index of BI group was significantly reduced compared with SB and CB groups after treatment.Conclusion:The SB has fewer disadvantages on peridentium than CB,while the BI is more conductive to protect the periodontal health status than SB and CB.