What Causes Blackening of the Gingival Tissue?

　　In daily life, many patients notice that their gums appear black—a sign that is not normal and thus causes greater concern. This discoloration may result from oral ulcers, melanin deposition, chronic periodontal disease, or other factors. Patients should consult a dentist for a thorough examination of their teeth and gums; medication may be prescribed, and professional dental cleaning is necessary to remove dental plaque and calculus. So, what causes black gums?

　　What Causes Black Gums?

　　Black discoloration of the gums may stem from melanin deposition derived from hemoglobin within the body, manifesting as dark pigmentation on the gums. Typically, this condition is asymptomatic—without pain or swelling—and poses no threat to overall health. Alternatively, it may be caused by exogenous substances, such as metal-based porcelain-fused-to-metal (PFM) crowns used in dental restorations. Chronic release of metal ions from these restorations can lead to gingival darkening or blackening, potentially resulting in persistent black lines along the gumline that do not resolve spontaneously.

　　Cases of lead poisoning are rare but noteworthy: once lead enters the bloodstream and is absorbed systemically, it may deposit along the gingival margin, forming a characteristic bluish-black line (known as Burton’s line). Diagnosis requires blood testing. Additionally, poor oral hygiene may lead to subgingival calculus accumulation; because this calculus tends to be darkly pigmented and the overlying gingiva is thin, the gums may appear black.

　　If any symptoms suggestive of disease are observed in daily life, prompt medical evaluation and active cooperation with treatment are essential. We hope this information has been helpful to you.