Burcak Cengiz Sevi, Stephan Atac Atilla, Cehreli Zafer C
Department of Pediatric Dentistry, Faculty of Dentistry, Baskent University, Ankara, Turkey.
Dent Traumatol. 2006 Jun;22(3):133-8. doi: 10.1111/j.1600-9657.2006.00339.x.
This study was undertaken to assess the effect of splint type on stresses occurring around traumatized tooth by photoelastic stress analysis. Three semi-rigid splint types--a wire-composite splint, fiberglass splint and titanium trauma splint--were utilized for comparisons. Extracted left upper central and lateral incisors and the canine tooth of an otherwise healthy patient were embedded equidistantly in photoelastic resin. For all cases studied, a static axial and 20 degrees oblique force of 100 N was applied on the lateral incisor in separate sessions. The experiments were undertaken without any splint application (unsplinted, control) after which the splints, adhesively bonded to the labial aspects of teeth, were consecutively tested. During each loading sequence, generation of isochromatic fringes was observed in the field of a polariscope, and photographed by a digital camera. Quantification of fringes was performed on magnified images, transferred to a PC. Under vertical loading, the highest stresses in the apical regions were observed for the unsplinted and ribbond-splint groups, whereas the lowest fringes occurred with the use of orthodontic wire as a splinting medium. Titanium trauma splint had absolutely no effect on reduction of stresses, as the fringe orders were slightly higher than the unsplinted lateral tooth. The use of orthodontic wire resulted in lowest fringe orders around the traumatized tooth.
本研究旨在通过光弹性应力分析评估夹板类型对创伤牙周围应力的影响。使用了三种半刚性夹板类型——钢丝 - 复合夹板、玻璃纤维夹板和钛制创伤夹板——进行比较。将一名健康患者拔除的左上中切牙、侧切牙和尖牙等距嵌入光弹性树脂中。对于所有研究病例，在不同时段分别对侧切牙施加100 N的静态轴向力和20度斜向力。先在未使用任何夹板（无夹板，对照）的情况下进行实验，之后将夹板通过粘接固定在牙齿唇面并依次进行测试。在每个加载序列中，在偏光镜视野中观察等色条纹的产生，并用数码相机拍照。在放大图像上对条纹进行量化，然后传输到个人电脑上。在垂直加载下，未使用夹板组和丝带夹板组在根尖区域观察到最高应力，而使用正畸钢丝作为夹板介质时条纹最少。钛制创伤夹板对降低应力完全没有效果，因为条纹级数略高于未使用夹板的侧切牙。使用正畸钢丝导致创伤牙周围的条纹级数最低。
