[Amalgam tattoo--an important differential diagnosis from malignant melanoma of the mouth mucosa].

Amalgam tattoos develop as an amalgam deposit often as a result of continuous contact between an amalgam filling and the gingiva or amalgam fragments embedded in the oral tissue during dental filling or surgical operations. Sometimes fragments of amalgam restorations are broken off during extraction and embed in the adjacent soft tissue. In our case a small piece of amalgam had broken off during an extraction after retrograde filling up this tooth some years before following a resection of the dental root. Embedded in the depth of the bony resection cavity the piece of amalgam had produced the amalgam tattoo 13 years later.