Cucu M, Driessen C H, Ferreira P D
Department of Orthodontics, University of Göteborg, Sweden.
SADJ. 2002 Jan;57(1):16-20.
Previous studies have shown that the size of the foil mesh and surface area of the bracket base correlated to bond strength to tooth enamel. The purpose of this study was to investigate the in vitro shear bond strength (SBS) of orthodontic brackets with 80 and 100 gauge mesh bases as well as mini and standard size bases. Eighty extracted human premolar teeth were randomly allocated into four groups of twenty teeth each. Premolar brackets of different mesh and bracket base area sizes were bonded to the enamel with a conventional 'two paste' orthodontic bonding agent. The SBS was determined and the bond failure sites were assessed using light-optical microscope and SEM. Bond failure occurred in all groups primarily at the bracket/adhesive interface. Mean values for SBS were 9.97 +/- 2.94 MPa and 10.72 +/- 2.54 MPa for 80 gauge mini and standard size respectively, and 10.45 +/- 3.27 MPa and 11.39 +/- 3.32 MPa for 100 gauge mini and standard size. A one-way ANOVA and an unpaired t-test revealed no significant difference in mean SBS (P > 0.05) between 80 and 100 gauge mini and standard size brackets, and no significant difference in mean SBS between brackets of the same surface area with a different gauge mesh size. The clinical relevance of this finding is that the clinician can select smaller brackets with no reduction in effectiveness of the treatment procedure.
以往研究表明，托槽基底的箔网尺寸和表面积与牙釉质的粘结强度相关。本研究的目的是调查具有80号和100号网底以及迷你型和标准型尺寸基底的正畸托槽的体外剪切粘结强度（SBS）。80颗拔除的人类前磨牙被随机分为四组，每组20颗牙。使用传统的“双糊剂”正畸粘结剂将不同网底和托槽基底面积尺寸的前磨牙托槽粘结到牙釉质上。测定SBS，并使用光学显微镜和扫描电子显微镜评估粘结失败部位。所有组的粘结失败主要发生在托槽/粘结剂界面。80号迷你型和标准型尺寸的SBS平均值分别为9.97±2.94MPa和10.72±2.54MPa，100号迷你型和标准型尺寸的SBS平均值分别为10.45±3.27MPa和11.39±3.32MPa。单向方差分析和非配对t检验显示，80号和100号迷你型和标准型尺寸托槽之间的平均SBS无显著差异（P>0.05），相同表面积但网底尺寸不同的托槽之间的平均SBS也无显著差异。这一发现的临床意义在于，临床医生可以选择较小的托槽，而不会降低治疗程序的有效性。
