Noticing a change in tooth color, especially dark spots appearing black or deep brown, often prompts worry about dental health. Changes in tooth color occur for a variety of reasons, ranging from simple surface deposits to changes within the tooth structure itself. Any alteration in your tooth’s appearance signals a need for professional assessment to determine the exact cause and appropriate course of action.
The Direct Answer: When Black Spots Signal Decay
A black spot can be a sign of dental caries (a cavity), resulting from acid-producing bacteria eroding the enamel and dentin. The spot’s appearance helps differentiate between progressing and stabilized decay. Active decay, which requires intervention, typically appears lighter in color, often dull, and has a softer texture when assessed by a dental professional. This soft texture indicates that the demineralization process is ongoing.
A dark black or deep brown spot that feels hard and firm often represents arrested caries. Arrested decay is a lesion that was once active but stopped progressing due to factors like improved oral hygiene or fluoride, allowing the area to remineralize and harden. This type of lesion is characterized by a shiny surface because the decay process is no longer active and the structure is stable. While any black spot warrants examination, the hard, shiny nature of arrested lesions usually means a restorative filling is not necessary.
Non-Carious Reasons for Tooth Discoloration
Not every dark area is a sign of bacterial destruction; many black spots are due to external or internal discoloration unrelated to active decay. Extrinsic staining involves the outer surface of the enamel and is a common cause of dark spots where pigments easily adhere. Substances like coffee, tea, red wine, and tobacco contain chromogens that become embedded in the enamel. Certain medications, such as liquid iron supplements or antiseptic mouthwashes containing chlorhexidine, can also lead to surface discoloration.
A frequent cause of dark surface deposits is the buildup of dental calculus, also known as tartar. Plaque that is not removed hardens near the gumline and traps pigments, often presenting as a dark stain. Intrinsic discoloration occurs within the tooth structure itself, affecting the underlying dentin layer. This can result from excessive fluoride exposure (dental fluorosis), developmental defects of the enamel (hypoplasia), or internal bleeding following dental trauma.
What to Expect at the Dentist
A dental professional determines the nature of a black spot through a systematic diagnostic process. The initial assessment involves a thorough visual inspection to evaluate the spot’s size, location, and surface characteristics. This is followed by a tactile assessment, where a specialized instrument is used to gently probe the spot to determine if the surface is soft (active decay) or hard (arrested decay or stain).
To assess the internal structure, bitewing or periapical X-rays are routinely used. X-rays reveal the depth of any demineralization or decay beneath the enamel surface that is not visible externally. The combination of these diagnostic tools directs the subsequent course of action.
If the spot is identified as an extrinsic stain or calculus, professional cleaning and polishing are the primary treatments. For arrested decay, the dentist will recommend monitoring the spot during subsequent visits to ensure the condition remains stable. If the assessment confirms active, progressing decay, intervention is necessary, usually involving a restorative procedure like a dental filling to remove the compromised structure and seal the tooth.