Bishara S E, Olsen M, Von Wald L
Department of Orthodontics, University of Iowa, College of Dentistry, Iowa City 52242-1001, USA.
Am J Orthod Dentofacial Orthop. 1997 Dec;112(6):617-21. doi: 10.1016/s0889-5406(97)70226-9.
In an attempt to save chairside time during bonding, orthodontists are using ceramic and metal brackets that have been precoated with the adhesive material. The adhesive used on the precoated brackets is similar in composition to that used for bonding uncoated brackets; the difference is essentially in the percentages of the various ingredients incorporated in the material. The purpose of this study is to determine whether these changes in composition affect the shear bond strength and the site of bond failure when precoated and uncoated ceramic and metal brackets are used. Eighty-five recently extracted human molars were bonded according to the manufacturer's instructions and mounted in phenolic rings. An occlusogingival load was applied to the bracket, producing a shear force at the bracket-tooth interface with a Zwick Universal Test Machine. After debonding, all teeth and brackets were examined under 10x magnification. Any adhesive remaining after bracket removal was assessed with the Adhesive Remnant Index (ARI). The current findings indicated that: (1) Precoated ceramic brackets that used a slightly modified adhesive have similar shear bond strengths as that provided by Transbond XT adhesive on uncoated brackets; (2) precoated metal brackets that used the same adhesive have significantly lower shear bond strength than those obtained with Transbond XT on uncoated brackets. The differences in the bond strength between the ceramic and metal brackets were attributed to the combined effects of the changes in the composition of the adhesives used and in the retention mechanisms incorporated in the bracket bases of the different types of brackets; (3) all bracket/adhesive combinations tested provided clinically acceptable shear bond forces.
为了在粘接过程中节省椅旁时间，正畸医生正在使用预先涂覆了粘接材料的陶瓷和金属托槽。预涂托槽上使用的粘接剂在成分上与用于粘接未涂覆托槽的粘接剂相似；不同之处主要在于材料中各种成分的百分比。本研究的目的是确定当使用预涂和未涂覆的陶瓷及金属托槽时，这些成分变化是否会影响剪切粘接强度和粘接失败的部位。按照制造商的说明，将85颗近期拔除的人磨牙进行粘接，并安装在酚醛环中。使用Zwick万能试验机对托槽施加咬合龈向载荷，在托槽与牙齿的界面处产生剪切力。脱粘后，在10倍放大倍数下检查所有牙齿和托槽。用粘接剂残留指数（ARI）评估托槽去除后残留的任何粘接剂。目前的研究结果表明：（1）使用略有改性粘接剂的预涂陶瓷托槽的剪切粘接强度与未涂覆托槽上的Transbond XT粘接剂提供的强度相似；（2）使用相同粘接剂的预涂金属托槽的剪切粘接强度明显低于未涂覆托槽上使用Transbond XT获得的强度。陶瓷托槽和金属托槽之间粘接强度的差异归因于所用粘接剂成分变化以及不同类型托槽托槽基底中固位机制的综合影响；（3）所有测试的托槽/粘接剂组合都提供了临床上可接受的剪切粘接力。
