Interaction of Peroxides with Amalgam: A Case Report

Abstract

Nightguard vital bleaching with 10% carbamide peroxide was shown to have some minor effects on certain brands of amalgam mainly related to mercury release. However, in this case report, amalgam staining of the bleaching tray was detected in correspondence of the left and right first upper molars following tooth whitening for a week. These teeth presented mesio occlusal distal amalgam fillings with superficial chipping at the cavosurface margins. The same phenomena did not occur in the mouth with other amalgam intracoronal restorations not showing marginal defects. No decay or discoloration was noted around the amalgam fillings both in the upper and lower teeth. At the 1-week recall visit, patient was recommended to avoid the bleaching gel application in the maxillary first molar teeth. The existing fillings were replaced with composite resin restorations after a 2-week elapse time. The unusual amalgam staining of the bleaching tray suggests that amalgam restorations with defective cavosurface margins should be monitored during the tooth whitening therapy. Alternatively, their replacement should be considered prior to bleaching.