氢氧化钙和MTA修复比格犬髓室底穿孔的组织病理学观察

Furcation perforation repair ability of Cav-Hycal and MTA in Beagle dog teeth using histological method

目的:从组织病理学角度评价氢氧化钙和MTA修复比格犬髓室底穿孔的效果。方法:3只成年比格犬,36个前磨牙以象限为单位随机分配到氢氧化钙组和MTA组,分别以2种材料修复髓室底人工穿孔;12个磨牙设为阳性对照,以聚氯乙烯膜覆盖人工穿孔;12个磨牙设为阴性对照,不穿孔。术后1、4、12周制作组织病理切片,光学显微镜下观察组织病理改变。结果:术后1周,氢氧化钙组、MTA组及阳性对照组未见明显改变。术后4周,氢氧化钙组6例在穿孔下方有纤维组织形成,伴轻至中度炎症反应;MTA组3例有牙骨质形成,2例新骨形成,无或轻度炎症反应;阳性对照组4例有骨吸收伴中度炎症反应。术后12周,氢氧化钙组2例上皮增生伴中度炎症反应、3例纤维组织修复、1例新骨形成;MTA组2例上皮增生伴中度炎症反应、2例有牙骨质形成,4例有新骨形成;阳性对照组4例上皮增生伴重度炎症反应。结论:MTA能诱导比格犬髓室底穿孔处牙骨质、牙槽骨的再生,效果优于氢氧化钙。

AIM：Furcation perforation models were created in Beagle dog teeth to investigate the histological responses to Cav-Hycal or MTA.METHODS：Perforations were made at the pulp chamber floors of 36 premolars and 12 molars in three adult Beagle dogs.The 36 premolars were randomly divided into two groups in terms of quadrants and were repaired immediately with either Cav-Hycal or MTA.The furcation in 12 molars was covered with polyvinyl chloride membrane（positive control group）.Another 12 molars without furcation perforation served as negative contral.The dogs were sacrificed at 1,4 or 12W and perforation-invovled tissues were sectioned before the specimens were examined under light microscopy.RESULTS：In the Cav-Hycal group,the specimens showed mild inflammation at 1-week.Most of specimens showed mild to moderate inflammation at 4-week and the damaged tissue was replaced by fibrous connective tissue.At 12-week,epithelial proliferation was seen in two cases,fibrous tissue in three cases and bone regeneration in one case.In the MTA group,mild inflammation was seen at 1-week.At 4-week,new cementum and bone were observed in three cases.New bone with no cementum was observed in one case.Fibrous tissue filled the other two perforations.At 12-week,epithelial proliferation was seen in two cases,new bone in four cases and new cementum in two cases.In the positive control group,the specimens showed mild inflammation at 1-week.At 4week,there was an extensive bone resorption with the presense of osteoclastic cells within resorption lacunae.The specimens showed moderate inflammation.At 12-week,epithelial proliferation with severe inflammation was seen in all cases.CONCLUSION：MTA is superior to Cav-Hycal for its immediate furcation perforation repair ability in Beagles owing to the ability to induce the formation of new cementum and bone.