Bond's Book of Oral Diseases, 4th Edition

Amalgam Tattoo

Diffuse steel-gray, poorly demarcated discoloration of mandibular mucosa.

ŠThe Maxillofacial Center for Education & Research
 

 

 



Quick

Quick Summary (for Patients)

The amalgam tattoo is a benign discoloration of the mouth membrane resulting from amalgam particles falling into small, open wounds created during dental treatment or by trauma shortly after a dental treatment, when small, fresh amalgam particles still cling to the mucosa.  Foreign particles may be large enough to be seen on x-rays and occasionally the tattoo is seen to expand over time as inflammatory cells beneath the membrane try to "clean up" the area.  No treatment is needed, but some persons may be intolerant to one or more components of the tattoo, which usually consists of mercury, silver and copper. 





Detailed Review

Introduction: Amalgam Tattoo

Note: click on underlined words for more detail or photos.

The implantation of dental materials into mildly injured or periodontally inflamed mucosal tissues during the restoration of carious teeth is not an unusual event. The material most likely to present as a mucosal discoloration is amalgam from the "silver fillings," hence, the lesion is usually called an amalgam tattoo, but other metals may produce the same effect. Most of the time these "biocompatible" materials do not illicit a local inflammatory response, but occasional cases are associated with chronic inflammatory changes compatible with a foreign body reaction. Amalgam is a combination of mercury, silver, tin, copper and, sometimes, zinc. The mercury usually comprises half of the mixture and rarely produces an obvious tissue necrosis despite its rather high level of toxicity in other settings. Overall, amalgam tattoo is found in approximately 1 per 1,000 adults (Table 1).



Clinical
F1_2
Clinical Features

The amalgam tattoo presents as a soft, painless, nonulcerated, blue/gray/black macule with no surrounding erythematous reaction (two figures to left). It is most frequently found on the gingival or alveolar mucosa, but many cases are seen on the buccal mucosa and no anatomic site is immune from this change. The tattoo is found more frequently in females than in males, perhaps because women more frequently seek dental care. It is also seen more frequently with advancing patient age, presumably because of increased exposure to dental amaltattooCgrube.jpg (11919 bytes)procedures over time.  The tattoo is only moderately demarcated from the surrounding mucosa and is usually less than 0.5 cm. in greatest diameter, although rare examples have been more than 3.0 cm. in size. Lesions with larger particles will be visible on routine dental radiographs.  

Some patients will demonstrate a long-term inflammatory response, with small discolored papules produced, and those who exhibit a strong macrophage response the discolored patch can enlarge over time as the macrophages engulf the foreign material and attempt to move it out of the area.

Occasional deposits of amalgam are found in bone, usually as a result of the material being inadvertently scraped from an adjacent restoration during tooth extraction of other surgical procedure, including the deliberate placement of amalgam into the apical canal of a root during endodontic surgery.  These become quickly blackened and may impart a black discoloration to the adjacent bone.



Pathology
Microscopic Features

The amalgam tattoo is characterized by an unencapsulated area of submucosal stroma with clusters of small black/brown rounded particles, often seen to coat blood vessels and reticulin fibers (first figure to left). Occasional larger, angular particles are seen, but seldom is there a noticeable inflammatory cell response. When present, this response is usually represented by chronic inflammatory cells aggregated in the areas of foreign material. Histiocytes and foreign body multinucleated giant cells may be associated with the amalgam particles, in which cases the lesion is said to be a foreign body reaction (second figure to left).  The giant cells can surround or engulf the metallic particles, and sometimes huge pieces can be seen within their cytoplasm.  Histiocytes also may be laden with the foreign material.  Neutrophils and eosinophils are not part of this reaction.

When particles are numerous enough, a diffuse and sometimes intense fibrosis occurs in a wide region around them.  This is especially noticeable when amalgam is embedded within bone marrow.  The fibrosis may be quite avascular and is often without lymphocytes.  The stroma around freshly embedded amalgam particles with show neovascularity and a more pronounced chronic inflammatory cell response. 



Treatment

Treatment and Prognosis

Once present, the amalgam tattoo remains indefinitely, and occasional lesions slowly enlarge over time, presumably as amalgam-laden histiocytes try to move the material out of the local site. No treatment is necessary, but excisional biopsy is often performed in order to rule out melanoma or another pigmented lesion. Lesions visible on radiographs are usually not biopsied and those occurring on the visible vermilion border of the lips are usually removed for aesthetic reasons. There is no malignant potential for this lesion.


References


References (Chronologic Order)

General references:

Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and maxillofacial pathology. Philadelphia, W. B. Saunders; 1995.

Sapp JP, Eversole LR, Wysocki GP. Contemporary oral and maxillofacial pathology. Mosby; St. Louis, 1997.

Odell EW, Morgan PR. Biopsy pathology of the oral tissues. London; Chapman & hall Medical, 1998.

Specific references:

Buchner A, Hansen LS. Amalgam pigmentation (amalgam tattoo) of oral mucosa: a clinicopathologic study of 268 cases. Oral Surg Oral Med Oral Pathol 1980; 49:139-147.

Harman LC, Natiella JR, Meenaghan MA. The use of elemental microanalysis in verification of the composition of presumptive amalgam tattoo. J Oral Maxillofac Surg 1986; 44:628-633.

Shiloah J, Covington JS, Schuman NJ. Reconstructive mucogingival surgery: the management of amalgam tattoo. Quintessence Int 1988; 19:489-492.

Slabbert H, Ackermann GL, Altini M. Amalgam tattoo as a means for person identification. J Forensic Odontostomatol 1991; 9:17-23.


Table 1



Table 1:  Gender-specific prevalence rates per 1,000 population for selected oral masses and surface alterations in U.S. adults, ranked by total frequency. Modified from Bouquot JE. Common oral lesions found during a mass screening examination. J Am Dent Assoc 1986; 112:50-57, and Bouquot JE, Gundlach KKH. Oral exophytic lesions in 23,616 white Americans over 35 years of age. Oral Surg Oral Med Oral Pathol 1986; 62:284-291.

Diagnosis

Number of lesions per 1,000 population*

Males

Females

Total

Leukoplakia

43.2

20.9

28.9

Torus palatinus 

13.2

21.7

18.7

Irritation fibroma

13.0

11.4

12.0

Fordyce granules

17.7

5.2

9.7

Torus mandibularis

9.6

7.9

8.5

Hemangioma

8.4

4.1

5.5

Erythema, inflammatory

4.5

4.8

4.7

Papilloma

5.3

4.2

4.6

Epulis fissuratum

3.5

4.4

4.1

Varicosities, lingual

3.5

3.4

3.5

Fissured tongue

3.5

3.1

3.2

Benign migratory glossitis

3.4

3.0

3.1

Aphthous ulcer

3.3

3.0

3.1

Traumatic ulcer

2.1

2.1

2.1

Papillary hyperplasia

1.7

3.8

3.0

Mucocele

1.9

2.6

2.5

Herpes labialis (herpes simplex)

2.4

2.6

2.5

Angular cheilitis

1.8

1.9

1.9

Smokeless tobacco keratosis

4.3

0.2

1.7

Hematoma or ecchymosis

2.0

1.4

1.6

Enlarged lingual tonsil

2.4

1.2

1.6

Chronic cheek bite

0.7

1.4

1.2

Lichen planus

1.2

1.1

1.1

Squamous cell carcinoma

2.5

0.1

0.9

Amalgam tattoo

0.6

1.0

0.9

Buccal exostosis

0.9

0.9

0.9

Leaf-shaped fibroma

0.4

1.2

0.9

Median rhomboid glossitis

0.8

0.5

0.6

Hairy tongue

1.2

0.3

0.6

Nicotine palatinus

1.2

0.2

0.6

Atrophic glossitis (smooth tongue)

0.6

0.5

0.6

Epidermoid cyst

0.7

0.4

0.5

Oral melanotic macule

0.5

0.3

0.4

Oral tonsils (except lingual)

0.5

0.3

0.4

Leukoedema

0.4

0.3

0.3

Lipoma

0.2

0.1

0.2

Ranula

0.2

0.1

0.2

Gingival hyperplasia

0.1

0.1

0.1

Buccinator node, hyperplastic

0.1

0.1

0.1

Pyogenic granuloma

0.0

0.07

0.04

Nasoalveolar cyst

0.0

0.07

0.04

Neurofibroma

0.0

0.07

0.04

* total examined population = 23,616 adults over 35 years of age