Protection mechanism of inflammation in Peri-implant tissue - Vascular changes in periodontium and peri-implant tissue incident to inflammation -

种植体周围炎被定义为影响种植体周围组织的炎症过程。本研究采用形态学研究技术，观察天然牙和种植体在实验诱导炎症后牙龈微血管的变化。在一只比格犬的下颌骨内植入了一颗钛螺钉。种植90天后，将牙线放置在种植固定物（种植周炎组）和天然牙齿（牙周炎组）的颈部，以增强牙菌斑的积累，持续90天。这些动物被血管注射了合成树脂。在扫描电子显微镜（SEM）下对所有树脂模型进行了检查。天然牙牙龈的维管网呈矩形网状排列。在牙周炎的情况下，血管直径扩张，牙龈血管网的排列改变为肾小球袢。对照侧种植牙的血管网与天然牙排列相似，形成致密的网络。在种植体周围炎中，可见扩张的肾小球血管袢形成。当种植体周围炎发生时，血管化的牙龈肉芽组织侵入骨-种植体界面，并与种植体周围的血管连接，加速骨吸收。这些结果表明，维持种植体周围组织抗炎症的功能和结构是困难的。细致的菌斑控制和对牙龈组织炎症的微循环的充分保护将确保种植体周围炎的治疗。

Peri-implantitis is defined as an inflammatory process affecting the tissues around a dental implant. In this study, microvascular changes of the gingiva in natural teeth and implant after experimental induction of inflammation are examined by morphological research techniques.A titanium screw implant was inserted into a Beagle dog's mandible. 90 days after implantation, dental floss was placed around the neck of an implant fixture (peri-inplantitis group) and natural teeth (periodontitis group) to enhance an accumulation of plaque for 90 days. The animals were given a vascular injection of the synthetic resin. All of the resincast models were examined under a scanning electron microscope (SEM).The vascular network of the gingiva of natural teeth was arranged in a rectangular net pattern. In the case of periodontitis, the diameters of the blood vessels were dilated and the arrangement of the gingival vascular network changed to glomerulus loops. The vascular network in implant gingiva of the control side formed a dense network as similar to the arrangement a of natural teeth. In the peri-implantitis, a dilated glomerulus vascular loop formation was observed. While peri-implantitis proceeded, vascularized gingival granulation tissue invaded the bone-implant interface and connected with vessels surrounding the implant to accelerate bone resorption.These results suggested that it is difficult to maintain the function and structure of peri-implant tissue against inflammation. Meticulous plaque control and adequate protection of microcirculation from inflammation in gingival tissues would assure that peri-implantitis would be amenable to treatment.