Peri-implantitis (PI) has been defined as an inflammatory lesion of the mucosa surrounding an endosseous implant and with progressive loss of supporting peri-implant bones. In recent years, histopathological differences between PI and periodontitis of natural teeth had been described in animal experiments and a certain number of human experiments. In this paper, we review the histopathological differences between PI and periodontitis reported in the existing literature and try to find the differences in the occurrence and progression of these two diseases. Overall, inflammatory cell infiltrate (ICT) is more extensive in PI than in periodontitis, extending to the alveolar ridge, with dense infiltration of plasma cells, lymphocytes, macrophages, polymorphonuclear leukocytes and a greater number of osteoclasts in the connective tissue, but with less vascular density within ICT than in periodontitis. In addition, foreign bodies are found in PI lesions. The histopathological differences between the two diseases in terms of inflammatory infiltration, vascularity, bone loss, and foreign bodies could partially explain the more rapid progression of PI than periodontitis, suggesting that PI should be taken seriously by physicians. Early diagnosis and treatment are essential to control the progression of PI. In addition, targeted therapy against specific inflammatory cells may become a new direction for PI treatment; reducing titanium particles released into peri-implant tissue by friction or electrochemical corrosion may help to prevent PI.
种植体周炎（peri-implantitis，PI）是指发生在种植体周组织与菌斑相关的病理状态，以种植体周黏膜炎症和进行性支持骨组织丧失为特征。近年来，PI与天然牙牙周炎的组织病理学差异在动物实验和一定数量的人体试验中得以描述，本文对现有文献报道的PI与牙周炎的组织病理学差异进行综述，并试图寻找两种疾病发生和进展的差异。总体而言，PI中炎性细胞浸润（inflammatory cell infiltrate，ICT）范围比牙周炎更大，一直延伸到牙槽嵴，结缔组织内有密集的浆细胞、淋巴细胞、巨噬细胞和多形核白细胞浸润，并含有更多数量的破骨细胞，但ICT内的血管密度小于牙周炎；另外，PI病变组织中发现异物的存在。两种疾病在炎症浸润、血管、骨丧失、异物方面的组织病理学差异，可以部分解释为何PI的进展较牙周炎更迅速，提示PI应引起临床医师的重视，早诊断早治疗对于控制PI进展至关重要。此外，针对特定炎症细胞的靶向治疗或可成为PI治疗的新方向；减少因摩擦或电化学腐蚀释放到种植体周组织中的钛颗粒有助于预防PI。.