A number of conditions may cause discoloration of the gingival.


Features to consider:

(1) focal, linear or diffuse

(2) temporary or persistent


Causes of linear blue/black/gray discoloration (relative to the gingival margin, punctate dots under magnification):

(1) lead line (Burton line): due to formation of lead sulfide

(2) bismuth

(3) mercury

(4) tattoo


Causes of diffuse discoloration:

(1) quinacrine (blue or purple)

(2) other drugs

(3) diet

(4) hemochromatosis

(5) racial (dark-skinned)

(6) Addison's disease



(1) chromogenic bacteria (periodontal)


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