RESUMO
Objective @#To analyze and discuss the effect of 4 different surface treatment methods on the bonding effect between polymerization porcelain and metal bracket s.@*Methods@# 45 polymer-ceramics specimens were made and 40 of them were selected and randomly divided into 5 groups according to different surface treatment methods. A group:surface without special treatment. B group: 9.6% hydrofluoric acid gel combine with bonding agent, C group: 9.6% hydrofluoric acid gel combine with silane, D group: 35％ phosphoric acid gel combine with bonding agent, E group: 35％ phosphoric acid gel combine with silane. All specimens were stored in water for 24 hours at 37 ℃ after bonding 10 min utes and then cycled 500 cycles (5 ℃ to 55 ℃). To measure the shear bonding strength and record the damage cases and the adhesive remnant index.@*Results @#The shear strength values were: 3.24 in the control group, 7.24 MPa in the hydrofluoric acid etching treatment group. 10.78 MPa in the hydrofluoric acid gel combined with silane group. 4.17 MPa in the phosphoric acid-only group, 6.84 MPa in the phosphoric acid gel combined with silane group. The results of each group were statistically different from those of the other four groups (P < 0.001). The rate of breakage after the removal of brackets of the hydrofluoric acid gel combined with silane group is higher than the others. @*Conclusion @#As to the high shear bonding strength and low rate of breakage after the removal of brackets, we recommend 35% phosphoric acid etching combining with silane coupling agent in clinical.