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

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 12671875
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 補綴理工系歯学
• Research Institution: NIIGATA UNIVERSITY (2002); Tokyo Medical and Dental University (2000-2001)
• Principal Investigator: UOSHIMA Katsumi NIIGATA UNIVERSITY Graduate School of Medical and Dental Sciences, Associate Professor, 大学院・医歯学総合研究科, 助教授 (50213400)
• Project Period (FY): 2000 – 2002
• Keywords: Dental Metal Allergy / Dental alloy / Dentin permeability / Allergen Removal / Metal abutment

Research Abstract

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.