Effect of MRI on Microleakage of Amalgam Restorations

OBJECTIVES: Due to the potential hazard imposed by the presence of ferromagnetic metals, patients with implanted metallic objects are excluded from Magnetic Resonance Imaging (MRI). However, amalgam restorations seem to be safe issues. The purpose of this study was to evaluate microleakage of amalgam restorations following MRI.

METHODS:63 human premolars freshly extracted were divided into 3 groups based on 3 high-copper amalgams: Cinalux (non gamma2, Spherical amalgam, Fagihi dental co, Iran) named as X, GS-80 (non gamma2 admix amalgam, SDI limited Australia) named as Y, Vivacap (non gamma2, spherical amalgam, Ivoclar Vivadent, Liechtenstein) named as Z in present study.The restorations were placed in the standard class 5 preparations on both buccal and lingual surfaces. The teeth were aged at room temperature in saline solution for two months, then sectioned mesiodistally.MRI applied just on half of each section randomly, and the other one kept as control. Following MRI all specimens immersed in dye solution, sectioned and scored for microleakage using stereomicroscope.

RESULTS: Wilcoxon test revealed significant differences in microleakage following MRI in Y and Z group but not in X group. However there was no significant difference between three groups with respect to microleakage score, Kruskal-Wallis test showed.

CONCLUSION: Based on this study it seems MRI is not completely safe technique concerning amalgam restorations specially aged fillings. Further investigations are recommended evaluating the effects of MRI on amalgam restoration`s microleakage.