IADR Abstract Archives
A preliminary study on the migration of metallic constituents originating from Ag-Pd-Cu-Au cast post: experimental study
Objectives:
Corroded metal ions from intra-oral restorations could stimulate metal allergic response. Since, the mechanism of the metal allergic disease is not yet understood in every details, removing the restorations which contain suspected allergen and expose in the oral cavity is still the gold standard treatment. In the case of metal cast posts that do not directly expose in the oral cavity, if their corroded ions in the root canal can permeate and invade periodontal tissue around the root, the allergic response might be triggered. To reveal whether removing the metal cast posts is necessary, the investigation of corroded metal in root dentin area around cast post is worthwhile.
Methods:
Two types of experiments were performed under static and electrochemical stimulation conditions. Twenty-five lower premolars were endodontically treated and cast posts were set thereafter. For static condition testing, five specimens were immersed in 0.9% sodium chloride for 6 months. The remaining twenty specimens were used for electrochemical stimulation testing at four different levels (150, 300, 500 and 1000 mV). All specimens were longitudinally sectioned and then the corroded metallic constituents in root dentin areas were investigated using an energy dispersive X-ray spectrometer and an electron probe micro analyzer.
Results:
In the case of static condition specimens, silver was detected at a depth of 30 µm. While electrochemically stimulated specimens, silver and copper were observed and the longest distance of invasion was 300 µm. Nonparametric Kruskal-Wallis analysis of variance showed a significant difference in the distance of invasion of silver among the four groups (P<0.05).
Conclusions:
These results suggest that the plausibility of corroded ions from Ag-Pd-Cu-Au cast posts invading outward along dentinal tubules to reach the root surface is low. Hence, removal of allergens containing cast post in the metal allergic patient may have a lower priority.
Corroded metal ions from intra-oral restorations could stimulate metal allergic response. Since, the mechanism of the metal allergic disease is not yet understood in every details, removing the restorations which contain suspected allergen and expose in the oral cavity is still the gold standard treatment. In the case of metal cast posts that do not directly expose in the oral cavity, if their corroded ions in the root canal can permeate and invade periodontal tissue around the root, the allergic response might be triggered. To reveal whether removing the metal cast posts is necessary, the investigation of corroded metal in root dentin area around cast post is worthwhile.
Methods:
Two types of experiments were performed under static and electrochemical stimulation conditions. Twenty-five lower premolars were endodontically treated and cast posts were set thereafter. For static condition testing, five specimens were immersed in 0.9% sodium chloride for 6 months. The remaining twenty specimens were used for electrochemical stimulation testing at four different levels (150, 300, 500 and 1000 mV). All specimens were longitudinally sectioned and then the corroded metallic constituents in root dentin areas were investigated using an energy dispersive X-ray spectrometer and an electron probe micro analyzer.
Results:
In the case of static condition specimens, silver was detected at a depth of 30 µm. While electrochemically stimulated specimens, silver and copper were observed and the longest distance of invasion was 300 µm. Nonparametric Kruskal-Wallis analysis of variance showed a significant difference in the distance of invasion of silver among the four groups (P<0.05).
Conclusions:
These results suggest that the plausibility of corroded ions from Ag-Pd-Cu-Au cast posts invading outward along dentinal tubules to reach the root surface is low. Hence, removal of allergens containing cast post in the metal allergic patient may have a lower priority.