Feldner J C, Sarkar N K, Sheridan J J, Lancaster D M
Universitätsklinik für Zahn- Mund- und Kieferheilkunde, Graz, Austria.
Am J Orthod Dentofacial Orthop. 1994 Sep;106(3):265-72. doi: 10.1016/S0889-5406(94)70046-X.
The purpose of this study was to investigate the torque-deformation characteristics of the following four types of polycarbonate brackets: (1) pure polycarbonate, PPC (anterior Miura, RMO, Denver, Colo.), (2) ceramic reinforced polycarbonate, CRPC (Silkon bracket, American, Sheboygan, Wis.), (3) metal slot reinforced polycarbonate, MRPC (Plastic bracket, Tella Tech, Miami, Fla.), and (4) metal slot and ceramic reinforced polycarbonate, MCRPC (Spirit, Ormco, Glendora, Calif.). A stainless steel bracket, (Mini Diamond, Ormco, Glendora, Calif.), was used as a control. Ten brackets of each type were tested. Each bracket was bonded to a porcelain tooth and engaged in a torquemeter. The tooth-bracket assembly was made stationary by embedding it in die stone. Torsion was applied to the bracket at 4 degrees per minute and the resultant torque (grams.centimeters) and deformation (degree) were measured. For optimum labiolingual tooth movement for a maxillary incisor at 175 grams . centimeters, the amount of angular deflection necessary for the different polycarbonate brackets was the following: (a) 15 degrees for MRPC, (b) 17 degrees for MRPC, (c) 24 degrees for CRPC, and (d) > 30 degrees for PPC. The amount of deformation at this deflection was the least for MRCP followed by MCRPC, CRCP, and PPC. When compared with the stainless steel bracket, all polycarbonate brackets showed significantly (p < 0.0001) higher deformation and lower torque. Within the polycarbonate group, there was a significant difference (p < 0.0001) between each bracket for both measurements. The MRPC produced the highest torque and lowest deformation values followed by the MCRPC, CRCP, and PPC. It appears that only the metal slot reinforced brackets are clinically capable of torquing teeth sufficiently.
本研究的目的是调查以下四种类型聚碳酸酯托槽的扭矩 - 变形特性：（1）纯聚碳酸酯，PPC（前田三浦式，RMO，科罗拉多州丹佛市）；（2）陶瓷增强聚碳酸酯，CRPC（Silkon托槽，美国威斯康星州希博伊根市）；（3）金属槽沟增强聚碳酸酯，MRPC（塑料托槽，Tella Tech，佛罗里达州迈阿密市）；以及（4）金属槽沟和陶瓷增强聚碳酸酯，MCRPC（Spirit，奥美科，加利福尼亚州格伦多拉市）。使用一个不锈钢托槽（Mini Diamond，奥美科，加利福尼亚州格伦多拉市）作为对照。每种类型的托槽测试10个。每个托槽粘结到一颗瓷牙上并安装在扭矩仪中。通过将牙 - 托槽组件嵌入石膏使其固定。以每分钟4度的速度对托槽施加扭矩，并测量产生的扭矩（克·厘米）和变形（度）。对于上颌中切牙在175克·厘米时实现最佳唇舌向牙齿移动，不同聚碳酸酯托槽所需的角偏转量如下：（a）MRPC为15度，（b）MCRPC为17度，（c）CRPC为24度，（d）PPC大于30度。在此偏转时，变形量最小的是MRCP，其次是MCRPC、CRCP和PPC。与不锈钢托槽相比，所有聚碳酸酯托槽均显示出显著更高的变形（p < 0.0001）和更低的扭矩。在聚碳酸酯组内，两种测量中每个托槽之间均存在显著差异（p < 0.0001）。MRPC产生的扭矩最高且变形值最低，其次是MCRPC、CRCP和PPC。似乎只有金属槽沟增强托槽在临床上能够充分对牙齿施加扭矩。
