GRAY/BLACK PIGMENTATIONS Amalgam Tattoo

GRAY/BLACK PIGMENTATIONS
Amalgam Tattoo
By far, the most common source of solitary or focal pigmentation in the oral mucosa is the amalgam tattoo. The lesions are macular and bluish gray or even black and are usually seen in the buccal mucosa, gingiva, or palate (Figure 6-12).

Importantly, they are found in the vicinity of teeth with large amalgam restorations or crowned teeth that probably had amalgams removed when the teeth were being prepared for the fabrication of the crown. Such lesions are the consequence of an iatrogenic mishap whereby the dentist’s bur, loaded with small amalgam particles that accumulate during the removal of amalgam, accidently veers into the adjacent mucosa and traumatically introduces the metal flecks. The metallic particles are quite fine, but in some instances (when large enough), they are identifiable on radiographs of the area. Amalgam fragments can also be deposited in oral tissue during multiple tooth extractions. Metal particles may fall unnoticed into extraction sockets, and during the healing phase, the amalgam becomes entombed within the connective tissue while re-epithelialization occurs. In these instances, radiography almost always demonstrates the presence of the metal.
Microscopically, amalgam tattoos show a fine brown granular stippling of reticulum fibers, particularly around vessel walls, and in many instances, large chunks of black metallic particles can be seen. A giant cell reaction is uncommon; however, a mononuclear inflammatory cell infiltrate is often noted.
Since amalgam tattoos are innocuous, their removal is not required, particularly when they can be documented radiographically. Alternatively, biopsy is recommended when a gray pigmented lesion suddenly appears or when such a lesion arises distant from any restored teeth; the differential diagnosis must include nevi and melanoma in such instances.