非血管化骨移植种植体以及即刻种植体与软组织结合的实验观察

目的:观察非血管化骨移植种植以及即刻种植体钛金属表面与软组织的结合状况,分析影响二者结合的因素。方法:拔除狗的一侧下颌前磨牙,4周后截除无牙下颌骨段,自体非血管化髂骨移植同时植入纯钛种植体修复下颌骨缺损。对照组动物拔除一侧下颌前磨牙时同期在牙槽窝内植入同样的种植体,缝合牙龈。在术后4、8、16周处死动物,以40g/L中性多聚甲醛灌注固定后,取种植体颈部周围软组织。肉眼观察2组动物种植体与周围软组织结合的紧密程度;HE染色观察结合上皮的组织结构;透射电镜观察结合上皮与种植体结合面细胞超微结构。结果:2组动物在术后4周时,种植体顶端已出龈暴露在口腔内,颈部周围的软组织已达初步封闭;两者的结合还较疏松,软组织较薄,细胞膜的表面突起较少。术后8周时,种植体的颈部软组织已完全封闭,软组织与钛表面结合紧密,即刻种植组动物可见明显的结合上皮;超微结构可见结合上皮有较多的细胞膜突起。术后16周,2组的结果与8周时相似。整个实验过程未发现桥粒结构的形成。结论:在没有明显创伤和感染的情况下,两者均可形成良好的结合;即刻种植体与周围软组织结合较非血管化骨移植种植体更致密。2种种植方法结合上皮与钛表面都不能形成桥粒结构。

Gingival conjunction with titanium implant after immediate dental implantation or delayed nonvascular bone graft with dental implantation

Objective:To observe the gingival conjunction with titanium implant after immediate dental implantation or delayed nonvascular bone graft with dental implantation.Methods: 12 dogs were divided into 2 groups with 6 in each group.The right 4 mandibular premolars were extracted,4 weeks after extraction, the edentulous mandible was cut off, the defects were reconstructed by nonvascularized ilium with simultaneous dental implantation in group A. The same dental implantation was performed immediately after tooth extraction in group B(control) and the gingiva was sutured. The animals were killed and specimens were obtained 4,8 and 6 weeks after implantation.Gingival- titanium conjunction was clinically observed and examined by microscope and transmission electron microscope (TEM).Results:4 week after implantation the top of dental implants was exposed,the neck of implants was primary sealed by thin and loose gingival tissue,processes of epithelial cells were small and few in the 2 groups.8 and 16 weeks after implantation, the neck of dental implants was completely sealed by tight gingival tissue, the more processes of epithelial cells could be seen in gingival- titanium conjunction area.The gingival- titanium conjunction in group B was denser than that in group A. No desmosome was found in the gingival conjunction during the 16-week observation.Conclusion:Both immediate dental implantation and delayed nonvascularized bone groft with dental implantation may result in clinical required gingival conjuction to titanium implant.