Department of Orthodontics, Faculty of Dentistry, University of Erciyes, Turkey.
Eur J Orthod. 2010 Jun;32(3):281-4. doi: 10.1093/ejo/cjp115. Epub 2010 Jan 15.
The aim of this in vitro study was to compare the shear bond strength (SBS) and failure modes of a conventional resin-based composite with a recently developed amorphous calcium phosphate (ACP)-containing orthodontic composite system. Forty freshly extracted human maxillary premolar teeth were randomly divided into two equal groups. Conventional composite (group 1; Transbond-XT; 3M Unitek) and ACP-containing orthodontic composite (group 2; Aegis-Ortho; Harry J. Bosworth Co.) were used for bonding ceramic orthodontic brackets. The SBS of these brackets were measured and recorded in megapascals (MPa). Adhesive remnant index (ARI) scores were determined after bracket failure. Data were analysed with a Student's t-test for two independent variables and Pearson's chi-square tests. Statistical analysis showed that the bond strength of group 1 (mean: 36.7 +/- 6.8 MPa) was significantly higher than group 2 (mean: 24.2 +/- 5.4 MPa; P < 0.01). Although a greater percentage of the fractures were cohesive at the composite interface (Score 1 + Score 2 = 70 per cent in group 1 and 90 per cent in group 2), statistically significant differences were observed between the groups (P < 0.05). The ACP system is suitable for bonding ceramic orthodontic brackets due to the lower SBS values compared with conventional composite. The ACP-containing composite is recommended for use in clinical orthodontic practice in order to achieve lower decalcification scores under ceramic orthodontic brackets.
本体外研究旨在比较传统的树脂基复合材料与最近开发的含非晶磷酸钙（ACP）的正畸复合材料系统的剪切结合强度（SBS）和失效模式。从 40 颗新鲜拔出的上颌前磨牙中随机均分为两组。使用传统复合材料（第 1 组；Transbond-XT；3M Unitek）和含 ACP 的正畸复合材料（第 2 组；Aegis-Ortho；Harry J. Bosworth Co.）粘结陶瓷正畸托槽。以兆帕斯卡（MPa）为单位测量并记录这些托槽的 SBS。托槽失效后确定黏附残余指数（ARI）评分。使用两独立变量的 Student's t 检验和 Pearson 卡方检验对数据进行分析。统计分析显示，第 1 组（平均值：36.7 +/- 6.8 MPa）的粘结强度明显高于第 2 组（平均值：24.2 +/- 5.4 MPa；P < 0.01）。尽管在复合材料界面处的断裂更多地是内聚性的（第 1 组的评分 1 + 评分 2 = 70%，第 2 组为 90%），但两组之间仍观察到统计学显著差异（P < 0.05）。与传统复合材料相比，ACP 系统由于较低的 SBS 值，适用于粘结陶瓷正畸托槽。为了在陶瓷正畸托槽下获得较低的脱矿化评分，建议在临床正畸实践中使用含 ACP 的复合材料。
