年轻恒前牙感染根管内血管再生的动物实验研究

Pulp revascularization of immature anterior teeth with apical periodontitis

目的通过建立根尖周炎模型观察年轻恒前牙根管内血管再生的组织学状况。方法选择4个半月龄杂种犬1只,建立上颌未发育完成的恒前牙根尖周炎模型,将6颗上颌恒前牙随机分组,对照组3颗采用根尖诱导成形术,实验组3颗采用根管内血管再生术。将术后1、4、8周的X线片分别与术前X线片进行对比,观察牙根继续发育及根尖炎症的愈合情况。术后8周处死动物,利用苏木精-伊红(HE)染色观察根尖闭合情况及根管内容物的构成。结果 X线观察,术后1、4周,2组牙根的根尖孔大小及根尖透射区范围未见明显改变。术后8周,实验组根尖透射区范围缩窄较明显,并出现根尖孔缩窄的趋势,但管壁厚度无明显变化;而对照组根尖透射区变化不一。组织学检查,实验组管腔内可见肉芽组织,其中包含有大量的不规则的类牙本质、类牙骨质和类骨质样钙化物,钙化物以根尖部和管腔内侧壁尤为明显。对照组管腔未见软组织,根尖部有少量的硬组织沉积。结论血管再生术可促使年轻无髓恒前牙的慢性根尖周炎症消退,根管内再生的肉芽组织中有硬组织沉积。

Objective To compare the therapeutic efficacy both apexification and revascularization in the imma-ture anterior teeth of animal model with apical periodontitis,and observe the histological situation of revascularization in the root canal.Methods Six immature anterior teeth of one animal model（dog） aged approximately 4.5 months was selected.Afterwards,periapical periodontitis pattern were established,the samples were randomly divided into the experimental group（revascularization,3 teeth） and the control group（apexification,3 teeth）.To compare the development of root and the healing of periapical inflammation,the involved teeth were respectively radiographed 1,4,8 weeks after surgery.The animals were sacrificed after 8 weeks,and the closure of apical foramen and the content of root canal were observed by hematine-eosine（HE） staining.Results The postoperative radiography after 1 week and 4 weeks,the apical foramen size and the periapical radiolucency of the samples was shown no perceptual change.After 8 weeks,the experimental group periapical radiolucency area was obviously more narrowing,and had a apical closure tendency whereas the thickness of the root canal walls had imperceptible changed.While the control group periapical radiolucency change varied.The granulation tissue could be seen within the lumen of the experimental group,which contained a large number of irregular calcification,the calcification was obvious in the apical and adjacent the root canal wall.A small quantity of hard tissue was deposited in the apical of the control group.Conclusion Revascu-larization may increase the recovery of immature anterior teeth with chronic periapical inflammation,the vital regenerative tissue within root canal is the granulation tissue contained calcification.