A grey discoloration of the gums is a noticeable change in oral tissue that warrants professional attention. While the mouth can exhibit various shades of pigmentation, a shift toward grey or blue-black is a sign that foreign material, a systemic issue, or an acute infection may be present. This color change is not always a sign of severe illness, but it often indicates an underlying condition that requires evaluation by a dental or medical professional. Understanding the difference between a localized stain and a widespread reaction is the first step toward determining the cause and necessary treatment.
Localized Discoloration from Foreign Material
Grey pigmentation confined to a single spot most often results from the accidental embedding of foreign materials. The most common example is the amalgam tattoo, which appears as a flat, painless macule that is blue-black or slate grey. These lesions occur when tiny fragments of silver amalgam, the material used in dental fillings, become lodged in the soft tissues during procedures.
The amalgam particle releases metallic ions into the surrounding connective tissue. These ions become trapped, creating a permanent, localized stain. While generally benign and requiring no treatment, these tattoos are often located on the gingiva or alveolar mucosa near a filled tooth. Another localized cause is a graphite inclusion, resulting from a traumatic injury, such as falling with a pencil in the mouth, leading to a dark macule where carbon material is embedded beneath the surface.
Systemic Causes from Medication and Toxicity
Diffuse pigmentation, or widespread grey discoloration, frequently points to substances circulating throughout the body that deposit in the oral soft tissues. One well-documented cause is the long-term use of the antibiotic minocycline, a tetracycline derivative often prescribed for acne or rosacea. Minocycline can cause a blue-gray or brown discoloration of the oral mucosa, as well as the teeth and bone, due to the formation of a complex that darkens upon exposure to light and oxygen.
This drug-induced pigmentation is typically linked to months of treatment and a high cumulative dose. Toxic exposure to certain heavy metals can also lead to systemic, grey-blue lines along the gum margins. Chronic lead poisoning, for instance, produces a characteristic black-blue line, called the Burton line, where circulating lead reacts with sulfur ions released by oral bacteria to form lead sulfide deposits in the marginal gingiva. A similar phenomenon, the bismuth line, can occur in patients who have ingested bismuth compounds, presenting as a thin, dark line along the gum tissue.
Acute Infections and Necrosis
A grey appearance signals tissue necrosis, or death, resulting from a severe bacterial infection. Acute Necrotizing Ulcerative Gingivitis (ANUG), historically called trench mouth, is a painful, rapidly destructive condition caused by an overgrowth of specific oral bacteria. The grey color is a visible sign of dead tissue sloughing off the gum surface.
This severe infection is characterized by a greyish, necrotic pseudomembrane that covers the tips of the gum tissue between the teeth. When this slough is wiped away, the underlying tissue is intensely red and bleeds easily. ANUG typically presents with sudden, excruciating pain, spontaneous gum bleeding, and an overwhelmingly foul odor in the breath. Systemic symptoms often accompany the oral signs, including fever, malaise, and swelling of the lymph nodes under the jaw. This condition is an opportunistic infection often triggered by factors such as severe psychological stress, poor oral hygiene, smoking, or a compromised immune system.
Necessary Diagnostic Steps and Urgent Care
A professional evaluation is necessary to accurately differentiate the causes of grey gums. The diagnostic process begins with a detailed medical and dental history, focusing on recent dental work, medication use, and potential occupational or environmental exposures to heavy metals. A visual examination determines if the discoloration is localized or diffuse and if it is associated with pain, swelling, or bleeding.
To confirm the cause, a healthcare provider may use tools such as dental X-rays to check for embedded metal fragments, such as with an amalgam tattoo. If a systemic cause is suspected, blood tests may be ordered to measure levels of heavy metals like lead or to check for other systemic diseases. For cases involving tissue changes, a small tissue sample, or biopsy, may be required to definitively rule out more serious conditions, such as melanoma, and to identify the specific nature of the pigmentation or necrosis. Immediate emergency care is required if the grey gums are accompanied by signs of acute infection, including rapidly spreading swelling, high fever, or severe, unmanageable pain.