Beagle犬双尖牙根分叉病变牙周炎模型的初步建立

Construction of experimental periodontitis model with root furcation infection of lower premolars in Beagle dogs

目的通过给Beagle犬肌注糖皮质激素及下颌双尖牙颈部弹力橡皮圈结扎等方法建立根分叉病变牙周炎模型，为低强度脉冲超声促进牙周组织再生实验提供研究平台。方法将4只Beagle犬随机分成糖皮质激素加结扎组及单纯结扎组，辅以高糖、高淀粉食物长期饲养，于7d和1、3、6个月分别检查Beagle犬的实验牙牙周情况，包括牙周临床指标检查和X线牙片检查。结果临床指标：糖皮质激素联合结扎组的Beagle犬实验牙牙周炎症较重，牙结石Ⅲ度，牙齿松动明显，根分叉暴露Ⅲ～Ⅳ度；而单纯结扎组实验牙牙结石Ⅰ度，牙齿松动不明显，根分叉暴露Ⅱ～Ⅲ度，牙周炎症相对较轻。X线牙片检查两组均可见牙槽骨的水平吸收，糖皮质激素联合结扎组牙槽骨水平吸收较多。结论糖皮质激素注射加牙颈部结扎和单纯的牙颈部结扎方法均可成功建立与临床相符的根分叉病变牙周炎模型，在相同时间内激素能加重牙周炎的临床症状并促进牙槽骨吸收。

Objective To establish the experimental periodontitis model with root furcation infection of lower premolars in Beagle dogs by intramuscular injection of glucocorticoid and orthodontic elastic ligation in dental cervix, and to provide the animal experimental model for regeneration of periodontium. Methods Four Beagle dogs were selected and randomly divided into two groups： glucocorticoid-ligation group and ligation group. High glucose regimen was used during the whole experiment in both groups. The periodontal clinical index and X-ray examination of experimental tooth were recorded on 7d, and 1, 3, 6 months. Resuits The periodontitis appeared more severe with calculus In o and significant tooth mobility in glucocorticoidligation group, exposure of root furcation Ⅲ-Ⅳ°; at the same time, calculus Ⅰ° and no significant tooth mobility, and root furcation exposure Ⅱ-Ⅲ° in ligation group was noticed. In both groups horizontal alveolar bone resorption could be observed by X-ray examination, and severe horizontal alveolar bone resorption appeared in glucocorticoid-ligation group. Conclusion Experimental periodontitis model with root furcation infection of lower premolars can be established by intramuscular injection of glucocorticoid and orthodontic elastic ligation in dental cervix, but glucocorticoid can aggravate the experimental periodontitis.