Influence of rebonded orthodontic brackets and different treatment methods on shear bond strength / 实用口腔医学杂志

ABSTRACT

Objective:To compare shear bond strength(SBS)of bonded and rebonded orthodontic brackets and influence of rebonded orthodontic brackets using different treatment methods on SBS.Methods:60 extracted premolars were evenly divided into three groups.Brackets were debonded with conventional techniques and then removed of residual adhesives from the base mesh using three different treatments.In groupⅠ,rebond a new bracket at the second,third bonding times.In group Ⅱ,remove residual adhesives from the base mesh with fire at the second,third times,then rebond the same bracket.In group Ⅲ,remove that using a tungsten carbide bur at the second,third times,then rebond the same bracket.Shear test was performed to compare the SBS and adhesive remnant indexes(ARI)among different groups.Results:The SBS of three groups at the first bonding sequence were(10.00?2.95)MPa,(9.57?2.45)MPa and(9.09?2.58)MPa.The SBS at the second,third debonding sequence in group I,group II,and group III were(9.55?2.84)MPa and(10.32?2.59)MPa,(7.30?2.15)MPa and(7.14?1.93)MPa,(12.13?2.93)MPa and(12.86?3.08)MPa,respectively.In group Ⅱ,the SBS was significantly lower,however,in group Ⅲ,the SBS was significantly higher,and the results showed significant differences(P