The Influence Of Different Base Designs And Adhesives On The Bond Strength Of Metallic Orthodontic Bracket

Objective:The purpose of this study was to investigate the influence of different base designs and adhesives on the bond strength of metallic orthodontic bracket.Methods:Eighty extracted human premolars were randomly and evenly divided into A1,A2,B1,B2,C1,C2,D1,D2 eight groups,each group 10 premolars and 10 brackets. Group A, B were bonded with Jingjin self-cured composite resin;group C,D with UniteTM self-cured composite resin;and group A,C with foil mesh base brackets,group B,D with laser base brackets.After being exposed to artificial saliva for 24 h,the bracket's shear bond strength(SBS)was tested in group A1,B1,C1,D1,the tensile bond strength(TBS)was tested in group A2,B2,C2,D2.The adhesive remnant index(ARI)of each bracket was recorded.Results : The adhesive resins has little effect on the bond strength of bracket(P>0.05). Design of bracket base structure significantly affects the bond strength.the SBS of foil mesh base bracket were greater in both groups(P<0.05).No difference of the ARI scores in SBS test or TBS test was found(P>0.05).Conclusion:The factor of bracket base design has significant influence on bracket's bond strength,and the bond strength of simple foil mesh bracket with micro-etch base is better than laser base bracket.In this experiment condition , there are no difference of Jingjin self-cured composite resin and UniteTM self-cured composite resin on influence of bracket's bond strength. The two adhesives all can meet the clinical adhesive requirement.