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.

Iron is an essential element for living organisms that plays critical roles in the process of bacterial growth and metabolism. However, it remains to be elucidated whether piuB encoding iron-uptake factor is involved in iron uptake and pathogenicity of Xanthomonas axonopodis pv. glycines (Xag). To investigate the function of piuB, we firstly generated a piuB deletion mutant (ΔpiuB) by homologous recombination. Compared with the wild-type, the piuB mutant exhibited significantly reduced growth and virulence in host soybean. The mutant displayed markedly increased siderophore secretory volume, and its sensitivity to Fe³⁺, Cu²⁺, Zn²⁺ and Mn²⁺ was significantly enhanced. Additionally, the H₂O₂ resistance, exopolysaccharide yield, biofilm formation, and cell mobility of ΔpiuB were significantly diminished compared to that of the wild-type. The addition of exogenous Fe³⁺ cannot effectively restore the above characteristics of ΔpiuB. However, expressing piuB in trans rescued the properties lost by ΔpiuB to the levels in the wild-type. Taken together, our results demonstrated that PiuB is a potential factor for Xag to assimilate Fe³⁺, and is necessary for Xag to be pathogenic in host soybean.
Iron ; Glycine max ; Virulence ; Xanthomonas axonopodis/genetics* ; Hydrogen Peroxide