壳聚糖用于乳牙活髓切断的实验研究

Experimental study of chitosan on vital pulpotomy in primary teeth

目的研究壳聚糖作为乳牙活髓切断盖髓剂的作用效果和反应,为研制生物型乳牙活髓保存剂奠定实验基础。方法壳聚糖生物反应性实验:新西兰兔6只,随机选择背部一侧肌肉植入壳聚糖试条,另一侧植入氢氧化钙试条,分别于术后1、2、4周处死动物,取植入物及周边组织行组织病理学检查。壳聚糖乳牙盖髓实验:5月龄小型猪8头,以双侧上、下颌乳磨牙为实验牙,共32颗,行活髓切断术;随机选择一侧乳磨牙16颗用壳聚糖盖髓;对侧同名牙用氢氧化钙糊剂盖髓。分别于术后1、2、4、8周处死动物,取实验牙及周边组织行组织病理学观察。结果壳聚糖生物反应性实验:4周时壳聚糖周围组织炎症反应减弱,纤维包裹变薄;氢氧化钙周围炎症反应变化不大,纤维包裹仍然较厚。壳聚糖乳牙盖髓实验:壳聚糖盖髓组可见修复性牙本质的形成。与氢氧化钙相比,壳聚糖盖髓后牙本质桥的形成早、速度快,且不引起浅表牙髓组织的坏死。结论壳聚糖作为乳牙活髓切断盖髓剂效果明显,生物相容性好,可促进修复性牙本质形成,有临床应用前景。

Objective To investigate the use of chitosan as pulp-capping agent on vital pulpotomy of primary teeth. Methods Two groups of animals were used in this test, rabbits and miniature pigs. In group one, chitosan pastes were randomly implanted into one side of the back muscles of 6 New Zealand rabbits. The other sides of the back muscles were used as control group with implantation of calcium hydroxide pastes. The rabbits were then sacrificed 1, 2, and 4 weeks after the implantation. Histological changes were observed on these rabbits. The second group consisted of 8 five- month old miniature pigs. One side of the 16 primary teeth was randomly selected as test group and chitosan used as pulp capping agent. The opposite side of the primary teeth served as control group and calcium hydroxide paste used as pulp capping agent. The miniature pigs were then sacrificed 1,2, 4 and 8 weeks after operation, and histological changes were observed. Results Tissue inflammatory reaction around chitosan was decreased 4 weeks after implantation, and the fibrous enwrapping became thin. The inflammation reaction around calcium hydroxide exhibited little change, and the fibrous enwrapping was still relatively thick. Restorative dentin formation was observed in chitosan group. Compared with calcium hydroxide, chitosan exhibited better biocompatibility. In chitosan capped teeth, the dentin bridge formed sooner and faster without causing superficial pulp tissue necrosis. Conclusion Chitosan can promote dentin formation and is suitable for pulpotomy as capping agent.