Abstract: Abstract：　Objective　By adding a strontium intensived bioactive glass to the orthodontic enamel adhesive resin and testing its antibacterial property and mechanical property, the study was trying to seek the proper proportion which can provide the theoretical basis for orthodontic clinical application. Methods　1%, 2%, 3%, 2% and 5%(mass fraction) of strontium intensived bioactive glass were respectively added into the enamel adhesive resin and were numbered as five experimental groups: group 1, 2, 3, 4, 5 and there was a control group: group 0 without adding strontium intensived of bioactive glass.Bacteriostatic ring method and sticking membrane?method were used to test the antimicrobial activity and the universal testing machine was used to test the shear strength of each group above; the study also observed and recorded the adhesive residue index (ARI). Results　Bacteriostatic ring did not appeare among all groups and sticking membrane?method measured the antibacterial rate indicating that the antibacterial rate of group 4 and group 5 were 99.9%. These two groups had strong antimicrobial properties. The shear strength of experimental groups had significant difference(P<0.05) comparing to control group 0 but the difference among experimental groups had no statistical significance (P>0.05), and the shear strength of each group can meet the clinical needs. The tooth surface of experimental groups and control group had enamel adhesive resin residual and ARI scores were from 2 to 4 and the ARI results had no statistically significant difference among groups (P>0.05). Conclusions　Adding 4%(mass fraction) of strontium intensived bioactive glass to orthodontic enamel adhesive resin had strong antibacterial effect and the shear strength can meet the need of orthodontic clinical but it had no effect on the amount of adhesive resin residue of enamel surface .

Key words: Strontium intensived bioactive glass, Othodontic enamel adhesive, Antibacterial property, Mechanical property