Brown spots on teeth are a common form of discoloration, ranging from faint patches to distinct dark marks. These spots vary significantly in shade, size, and location, presenting both a cosmetic and a potential health concern. Understanding the nature of this discoloration is the first step toward addressing it, as these spots have diverse origins classified as either external or internal to the tooth structure. The appearance of brown spots may signal a simple surface stain that can be polished away, or it may indicate a more serious issue like structural damage or underlying disease.
Surface-Level (Extrinsic) Causes
Extrinsic brown spots are stains that accumulate on the outer layer of the tooth enamel, often integrating with the acquired pellicle, a thin protein film that coats the teeth. The most frequent source of these stains is the consumption of chromogenic substances found in various foods and beverages. Compounds like tannins in red wine, coffee, and tea, or pigments in dark sodas, berries, and sauces, adhere to the enamel surface, causing discoloration over time.
Tobacco use is another contributor to deep brown or black extrinsic staining. The tar and nicotine present in smoking and chewing tobacco products adhere strongly to the microscopic pores within the enamel. These particles build up with repeated use, often resulting in heavy staining, particularly on the inner surfaces of the front teeth or near where smokeless tobacco is held.
Another common surface-level cause is the buildup of plaque and tartar (calculus). Plaque is a sticky biofilm of bacteria that, if not removed through regular brushing and flossing, hardens into porous tartar deposits. This calcified material absorbs stains easily from the diet, turning yellow, dark brown, or even black, and cannot be removed by simple at-home hygiene.
Structural and Internal (Intrinsic) Causes
Intrinsic brown spots originate within the tooth structure itself, often due to developmental issues, trauma, or disease, making them challenging to remove. A primary cause is dental caries (tooth decay), which begins when bacterial acid erodes the hard enamel. As the decay progresses into the underlying dentin, the softened tissue absorbs pigments and appears dark brown or black, signaling a need for restorative treatment like a filling.
Dental fluorosis is a developmental defect caused by ingesting excessive fluoride during tooth formation, typically before age eight. This over-exposure leads to hypomineralization of the enamel, resulting in a porous surface. Fluorosis can manifest as white streaks or, in severe cases, as permanent brown discoloration and pitting. Similarly, enamel hypoplasia is a defect where the enamel does not form to its full thickness, leaving the tooth surface rough, pitted, and vulnerable to staining that appears yellow-brown.
Certain medications can also cause intrinsic discoloration, most notably the antibiotic tetracycline. If taken by children while their permanent teeth are developing, or by a mother during pregnancy, the drug molecules incorporate into the dentin structure, leading to permanent, dark grayish-brown or banded discoloration. Trauma to the tooth can also cause internal bleeding within the pulp chamber, leading to pulp necrosis. This results in the tooth gradually turning a dark, internal color over time.
Professional Treatment Options
The approach to treating brown spots depends entirely on whether the discoloration is extrinsic (surface-level) or intrinsic (internal). For extrinsic stains caused by diet, tobacco, or plaque accumulation, the first line of treatment is a professional dental cleaning. This involves scaling to remove hardened tartar and polishing to smooth the enamel surface. Professional teeth whitening treatments, using high-concentration bleaching agents like hydrogen peroxide, can effectively break down pigment molecules, brightening most superficial brown stains.
Intrinsic stains embedded deeper within the dentin or due to structural defects require more complex interventions. For mild cases of fluorosis or other superficial internal stains, microabrasion may be used to gently remove a thin layer of the discolored enamel. For pronounced or widespread intrinsic discoloration that does not respond to bleaching, the dentist may recommend cosmetic solutions.
Dental bonding involves applying a tooth-colored composite resin directly to the tooth surface to cover the spot. For severe staining, structural damage from decay, or extensive hypoplasia, permanent restorations like porcelain veneers or crowns are necessary. Veneers are custom-made shells bonded to the front surface of the tooth, offering an aesthetic and durable way to mask the underlying brown spots.
Preventing Future Spots
Preventing the recurrence of brown spots centers on rigorous oral hygiene and lifestyle adjustments. Consistent and thorough oral care, including brushing twice daily and flossing once daily, is necessary to prevent the formation of plaque and subsequent tartar, which readily absorb stains. Regular six-month dental check-ups and professional cleanings are important for removing any early tartar buildup before it can darken and become established.
Dietary modifications are also effective in stain prevention. Reducing the intake of highly chromogenic beverages like coffee, tea, and red wine is beneficial. When consuming these drinks, using a straw can help limit contact with the teeth, and rinsing the mouth with water immediately afterward can wash away residual pigments and acids. Additionally, parents must monitor children’s fluoride intake during the developmental years to prevent fluorosis, ensuring they do not swallow fluoride toothpaste or consume excessive amounts from supplements or water sources.