Turn-over of tibiae bone around dental implante using nuclear image

牙种植体周围的骨变化尚未完全阐明。本研究旨在利用骨密度成像技术揭示种植体周围骨代谢的动态变化。将实验植入物插入Wister大鼠的胫骨中。为观察骨代谢活动，使用带有改进的高分辨率针孔准直器（针孔直径：2 mm）的γ照相机拍摄颅骨骨密度。静脉注射99 mTc-MDP（2 mCi/大鼠）。在注射后2小时进行冠状方向的静态平面采集。分别于种植体植入后4天、1、2、3、4周和5周进行影像学检查。获得骨整合后，植入物加载螺旋弹簧（100，150，200 g）。分别于术后4天、1周、2周、3周、4周和5周进行图像采集。计数99 mTc-MDP在种植体周围胫骨和对侧完整部位的蓄积量。计算各组种植体周围胫骨对完整部位的吸收率。研究表明，在插入后S周，植入部位的骨代谢恢复到与对侧完整部位相同的水平。植入后7 ~ 12天，种植体周围出现99 m-MDP的高峰蓄积。种植体周围的吸收率在不同类型的负载中是不同的。加载种植体后，种植体加载侧与牵引侧的应力值有显著性差异。骨显像显示种植体周围的胫骨对99 mTc-MDP的主动摄取。

Bone changes around the dental implants have not been fully elucidated. This study amid to reveal the dynamic change of bone metabolism around the implant using bone scintigraphy. Experimental implants were inserted in the tibiae of Wister rats. To observe the bone metabolic activity, bone scintigraphy of the cranium was taken using a gamma-camera with a modified high-resolution pinhole collimator (diameter of the pinhole: 2mm). 99mTc-MDP was injected intravenously (2 mCi/rat). Static planer acquisition in coronal direction was executed at 2 hours after the injection. The image takings were made at 4 days, 1, 2, 3, 4 weeks and 5 weeks after the implant insertion. After obtaining osseointegration, implants were loaded with coil springs (100,150,200g). The image takings were also made at 4 days, 1, 2, 3, 4 weeks and 5 weeks after loadings. Accumulation of 99mTc-MDP to the tibiae bone around the implant and the contralateral intact site were counted. Uptake ratio of the tibiae bone around the implant to the intact, site was calculated in each group. The study revealed that bone metabolism at, the implant site was returned to the same level as the contralateral intact site at Sweeks after the insertion. High peak accumulation of 99m-MDP was seen around the implant at from 7 to 12 days after insertion. Uptake ratio around the implant was differing among the different kind of loading. Furthermore, there was significant difference between the loading side and the traction side of implant after loading to implants. Turn-over of the tibiae bone around the dental implant was demonstrated with the active uptake of 99mTc-MDP by bone scintigraphy.