Studies on migration of metal ions originated from cast post and antigen presenting ability of periodontal ligament cells.

我们在金属过敏诊所治疗过敏患者已经超过14年了。目前，我们的一个主要问题是，如果金属没有直接暴露在口腔中，是否应该从过敏患者的口腔中取出含有过敏原的金属铸造桩。因为从牙齿中取出石膏柱是有一定风险的。本研究的目的是研究腐蚀离子从铸造桩沿牙根小管向外迁移的距离，以寻求金属过敏时铸造桩的移除指南。首先，我们使用最高分辨率的EPMA对拔牙后有金属桩的牙齿进行调查，并了解其治疗历史。然而，当我们检查牙齿切割表面时，没有检测到金属离子。然后我们用正畸拔牙进行了几种模拟口腔内条件的体外实验。就目前我们使用的最灵敏的机器而言，在几百微米的范围内，铸桩上的铜迁移到牙质上的程度可以忽略不计。我们不能断定铸桩的腐蚀金属离子不可能从根外表面逸出。然而，对于过敏患者，去除未暴露的石膏桩可能比其他治疗更不重要，因为患者不太可能接触到高浓度的过敏原。需要进一步的仔细调查。

We have been seeing allergic patients for more than fourteen years in our metal allergy clinic. Currently, one of our major questions is whether we should remove metal cast post that contains allergens out of allergic patient's mouth, in case of the metal is not directly exposed to the oral cavity. Because there should be certain risks removing cast post out of the tooth. The purpose of this study was to investigate the distance of corroded ions from cast post migrating outward along the root dentinal tubules to seek the guideline for removal of cast post in case of metal allergy.First, we investigated the extracted teeth that had metal post inside and whose treatment histories were known using the highest resolution EPMA. However, there were no detectable metal ions when we investigated the cut surface of the teeth. Then we carried out several types of in vitro experiments simulating intra oral mouth conditions using orthodontically extracted teeth. As far as we found using most sensitive machine we have currently, there were only negligible copper migrated to root dentine from cast post in several hundred micrometer. We could not conclude that there was no possibility for corroded metal ions from cast posts exit the outer root surface. However, the removal of cast posts that are not exposed, out of allergic patients may have less priority than other treatments because it is less likely for the patients to be exposed to the allergen at high concentration.Further careful investigations will be needed.