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目的：观察在1.96N水平力作用下感染微螺钉种植体-骨界面的组织学变化。方法：健康雄性杂种犬4只,在犬的双侧上颌尖牙近远中、第二双尖牙近远中颊侧骨板各植入微螺钉种植体1枚,共32枚。种植体颈部缠绕正畸橡皮圈及4-0缝合线以诱导炎症。选左侧为实验组,右侧为对照组。实验组用镍钛拉簧在2种植体间即刻施加1.96N的水平力,对照组不加力。分别于种植体植入后1、2、4和8周处死动物。采用HE染色法观察种植体-骨界面的组织学变化。结果：观察期内实验组2枚种植体松动,未脱落。1周时种植体周围牙龈黏膜组织均出现明显的红、肿等炎性反应。实验组1周时种植体出现大量的急慢性炎症细胞,毛细血管增生扩张,有少许新生纤维组织,越接近尖部炎性反应越轻;2周时中部压力侧骨质连续性破坏;4周时颈部见少量骨质破坏,同时有片状的新生骨形成;8周时颈部骨质破坏吸收,中部压力侧见纤维增生,排列杂乱。对照组骨质破坏较实验组轻。结论：微螺钉种植体在感染状态下,骨质的吸收由颈部向尖部进行;加力较不加力对骨质破坏严重。“,”Aim：To observe histological alterations of the tissue surrounding the metainfective microscrew implant loaded with 1.96 N horizontal force.Methods：Thirty-two microscrew implants were inserted into the upper canines vicinity at cuspidal and molar of 4 crossbred dogs,respectively,and cotton ligatures and rubber rings were placed around the healing-abutments to induce infection.Each two implants in left side were loaded with a horizontal force of 1.96 N immediately by superelastic nickel-titanium coil springs,and the right side was the control.The dogs were sacrificed at the 1st,2nd,4th,and 8th week to observe the bone-implant interface changes under optical microscope after HE staining.Results：Mobility of two microscrews was observed,but they did not lost.The microscopic features of the experimental group showed chronic inflammatory changes in the gum near to the implants at the 1st week,and some fibrous tissue could be seen and the inflammation was less in the tip of implants.Two weeks later,bone destruction were observed.At the 4th week,bone destruction were less.Connective tissues could be seen in middle of the implants in the experimental group at 8th week.The changes of the control group was mild.Conclusion：Bone absorption of microscrew implants after infection is from the neck to the tip,and bone destruction is more severe in the loaded areas.