Mesial movement of the rat molars using Ni-Ticoil spring:a model of orthodontic tooth movement
10.3969/j.issn.2095-4344.2014.27.013
- VernacularTitle:镍钛螺簧牵拉大鼠第一磨牙向近中移动：正畸牙移动模型
- Author:
Jiaohong DUAN
;
Yang ZHANG
- Publication Type:Journal Article
- Keywords:
biocompatible materials;
orthodontic anchorage;
molar;
models,animal
- From:
Chinese Journal of Tissue Engineering Research
2014;(27):4339-4344
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND:The establishment of model is very crucial in the orthodontic tooth movement experiment. The selection of force and control ing of anchorage may greatly affect experimental results.
OBJECTIVE:To establish an animal model for orthodontic tooth movement.
METHODS:Twenty Wistar rats were included in this study. The root of incisor teeth at upper jaw was dril ed and then threaded with a ligature wire (0.3 mm diameter), therefore the alveolar bone and two incisor teeth were ligated. The first molar at right upper jaw was also ligated using a ligature wire (0.2 mm diameter). The experimental teeth were randomly divided into four groups. A Sental oy closed-coil spring (10 g, 25 g, 50 g) was placed between the maxil ary incisors and the maxil ary first molar, respectively. Taking the incisor as the anchorage, the molars were given a mesial movement, and control group received no force. On day 14, the dental pulp, dentin and enamin resorption was analyzed with Image-Pro Plus software.
RESULTS AND CONCLUSION:A light force (10 g Ni-Ti coil spring) produced irregular enamel resorption and narrowed periodontal membrane space, whereas heavy force (25 g Ni-Ti coil spring) produced irregular dentin and enamel resorption, even heavier force (50 g Ni-Ti coil spring) produced apparent resorption at dental root, which affected the dentin. No statistical difference of the relative depth of dentin resorption was found between the 10 g group and the control group (P>0.05). The data between other groups showed statistical y significant differences (P<0.05). The mechanical union of the incisors and the mandibular bone efficiently prevents the continuous eruption of the upper incisors, which maintains the anchorage stability. Using Ni-Ti coil spring, a stable, scientific and reliable model of orthodontic tooth movement can be established through mesial movement of the first molars. The optimal force of 10 g is used to move the rat first molar mesial y.
