Pham Dennis, Bollu Prashanti, Chaudhry Kishore, Subramani Karthikeyan
Roseman University of Health Sciences, College of Dental Medicine, Henderson, NV, USA.
J Clin Exp Dent. 2017 Jul 1;9(7):e848-e854. doi: 10.4317/jced.53869. eCollection 2017 Jul.
The objective of this study was to evaluate the effect of orthodontic bracket base shape on shear bond strength and adhesive remnant index.
In this study using 140 bovine incisors, shear bond strength (SBS) of brackets with different base shapes (rectangle, flower, round, heart, diamond, star, and football) were measured with an Instron testing machine and tested until bond failure. Adhesive Remnant Index (ARI) scoring was evaluated after debonding to evaluate the location of bond failure. Descriptive and one-way ANOVA post-hoc Tukey statistical analyses were performed with a statistical significance set at ≤0.05.
Statistically significant difference in mean SBS in Newtons was observed for multiple base shapes (<0.05). The highest mean SBS (N ± SD) was observed in football and flower base shapes (73.83 N ± 53.46; 65.82 N ± 37.89 respectively); the lowest mean was observed with diamond and heart shapes (30.51 N ± 11.73; 33.28 N ± 16.89 respectively). When reported in Megaspascals, statistically significant difference was observed for rectangle base shape (3.54 MPa ± 2.69) when compared to all other base shapes.
Bracket base shape has an effect on SBS. Higher SBS (N) for rectangle, flower, and football base shape indicates even stress distributions throughout the bracket base. Base shape with a pronounced converging tip over the axial plane may contribute to the reduction in SBS due to increased peak stress concentration resulting in bond failure. Shaped brackets, Shear bond strength, Adhesive remnant index, WildSmiles®.
本研究的目的是评估正畸托槽底座形状对剪切粘结强度和粘结残留指数的影响。
在本研究中，使用140颗牛切牙，用英斯特朗试验机测量不同底座形状（矩形、花形、圆形、心形、菱形、星形和足球形）托槽的剪切粘结强度（SBS），并测试至粘结失败。脱粘后评估粘结残留指数（ARI）评分，以评估粘结失败的位置。进行描述性和单因素方差分析后的Tukey统计分析，设定统计学显著性水平≤0.05。
观察到多种底座形状的平均SBS（以牛顿为单位）存在统计学显著差异（<0.05）。在足球形和花形底座形状中观察到最高的平均SBS（N±SD）（分别为73.83 N±53.46；65.82 N±37.89）；在菱形和心形形状中观察到最低的平均值（分别为30.51 N±11.73；33.28 N±16.89）。以兆帕为单位报告时，与所有其他底座形状相比，矩形底座形状（3.54 MPa±2.69）存在统计学显著差异。
托槽底座形状对SBS有影响。矩形、花形和足球形底座形状的较高SBS（N）表明整个托槽底座的应力分布均匀。轴向平面上具有明显会聚尖端的底座形状可能由于峰值应力集中增加导致粘结失败，从而导致SBS降低。异形托槽、剪切粘结强度、粘结残留指数、WildSmiles®。
