Brown teeth can be caused by a variety of medical conditions that affect the health and appearance of teeth. In this article, we will examine some of the most common medical causes of brown teeth and what can be done to treat them.
Dental Fluorosis
One of the most common causes of brown stains on teeth is dental fluorosis. This condition occurs when children are exposed to excessive amounts of fluoride during the developmental stages of their permanent teeth. Too much fluoride can lead to changes in the mineralization of the teeth, causing white specks, yellowish stains, brown spots, and in severe cases, pitting of the tooth enamel.
Dental fluorosis only affects permanent teeth that are still developing under the gums. The excess fluoride becomes incorporated into the tooth structure. Primary (baby) teeth are not affected. In mild cases, fluorosis may only show up as nearly invisible white speckles on the enamel. Moderate fluorosis leads to more noticeable white spots and brown stains, while severe fluorosis causes dark brown stains, pitting, and a rough texture of enamel.
Fluorosis is most commonly caused by:
- Consuming too much fluoridated water, especially during the first 8 years of life when permanent teeth are developing
- Using too much toothpaste or inadvertently swallowing toothpaste
- Taking fluoride supplements when they are not needed
- Eating too many foods or drinks processed with fluoridated water
Since dental fluorosis only affects developing teeth, the condition cannot be reversed once the teeth have erupted. However, the appearance of mild to moderate fluorosis can often be improved through professional teeth whitening. More severe cases may require restorations such as dental veneers or crowns to improve appearance.
Tetracycline Staining
Tetracycline is a commonly prescribed antibiotic that can cause tooth discoloration as a side effect. Tetracycline becomes incorporated into teeth as they develop, producing yellow to brown bands or streaks in the enamel. This type of staining most often occurs in children under age 8 whose permanent teeth are still developing, but can affect anyone taking tetracycline while their teeth are forming.
There are several types of tetracycline antibiotics that can cause discoloration, including:
- Tetracycline
- Doxycycline
- Minocycline
- Demeclocycline
Tetracycline staining cannot be removed with normal teeth cleaning methods. Because the antibiotic is structurally bound to the teeth, the discoloration is permanent. However, there are several treatment options that can improve the appearance of tetracycline-stained teeth:
- Tooth whitening – In-office whitening treatments performed by a dentist are often effective at lightening tetracycline stains.
- Dental veneers – These thin porcelain shells are bonded to the front of teeth to cover stains.
- Dental crowns – Crowns fully encase discolored teeth to create an even, white smile.
Dental Caries
Dental caries, also known as cavities or tooth decay, can cause teeth to turn brown in severe cases of untreated decay. Cavities develop from plaque buildup on the teeth combined with frequent consumption of sugary or starchy foods. Bacteria in the plaque produce acids that break down the enamel and cause decay.
In the early stages, caries may appear as small white, brown, or black spots on tooth surfaces. As the decay worsens, it can take on a dark brown to black coloration. Advanced cavities may weaken the tooth until it collapses or necessitates extraction.
Regular dental cleanings and fluoride treatments can help prevent caries. If cavities do develop, they should be treated as soon as possible through fillings or crowns to remove decayed material and restore the teeth.
Celiac Disease
Celiac disease is an autoimmune disorder that causes damage to the small intestine when gluten is ingested. This can lead to poor absorption of nutrients, causing a variety of symptoms. In some people with celiac disease, tooth discoloration and enamel defects may occur.
It’s believed that nutritional deficiencies associated with celiac disease impair proper enamel formation and mineralization. Deficiencies in iron, vitamin D, calcium, and other nutrients can contribute to yellow, brown, or gray discoloration of teeth.
Strict adherence to a gluten-free diet can help improve nutrient absorption and nutritional status in celiac patients. Dental restorations like bonding, crowns, or veneers may also be recommended to cover tooth discoloration caused by the disease.
Drug-Induced Discoloration
Certain prescription drugs and over-the-counter medications can alter tooth color as a side effect of their use. The discoloration may show up as brown, gray, yellow, or black staining of the teeth.
Some types of drugs that can discolor teeth include:
- Antibiotics like tetracycline
- Antihistamines like Benadryl
- High blood pressure medications with trace metals
- Anticonvulsants
- Antipsychotics
- Chemotherapy drugs
Drug-induced tooth staining may be reversible after the medication is stopped. However, some residual discoloration can remain. Discuss any tooth color changes with your dentist and doctor. Switching medications or adjusting dosages may help resolve the issue. Professional whitening can also help brighten drug-stained teeth.
Amelogenesis Imperfecta
Amelogenesis imperfecta is a rare genetic disorder that affects enamel formation. It causes defects in the quantity, structure, and maturation of enamel. Teeth often appear discolored, pitted, or grooved.
There are several types of amelogenesis imperfecta, which are classified by inheritance pattern and specific enamel defect:
- Hypoplastic type – Thin, deficient enamel
- Hypomaturation type – Soft, poorly mineralized enamel
- Hypocalcified type – Undermineralized, soft enamel
Teeth affected by amelogenesis imperfecta are often sensitive and prone to discoloration and decay. Brown, yellow, or gray hues are common. Treatments aim to protect teeth and improve appearance, including:
- Crowns over discolored, weakened teeth
- Bonding to cover defects
- Veneers to mask imperfections
- Tooth-colored fillings
Dentinogenesis Imperfecta
Dentinogenesis imperfecta is a genetic disorder that affects dentin formation, causing discolored, translucent teeth. Dentin is the bony layer under tooth enamel that makes up the bulk of the tooth.
In dentinogenesis imperfecta, the dentin is improperly formed, causing teeth to appear gray, brown, or blue-gray. Teeth often chip and break easily due to defective dentin. The edges of front teeth may also appear rounded or bulbous.
There is no cure for dentinogenesis imperfecta. Management involves protecting the fragile teeth from fracture and improving appearance. Treatment methods include:
- Crowns over damaged teeth
- Bonding to stabilize chipped edges
- Veneers or composite restorations to mask discoloration
Ongoing dental care is important to maintain the restorations and prevent issues like tooth decay, which can further damage the weakened teeth.
Pulp Necrosis
Pulp necrosis refers to death of the pulp tissue inside a tooth. It is most often caused by severe tooth decay, cracks or chips in the enamel, or traumatic injury to a tooth.
When the pulp tissue dies, the tooth can take on a dark gray, brown, or black coloration. This happens because the pulp provides nourishment and keeps the tooth vital. When it decays, blood flow is cut off and the tooth essentially begins to die from the inside out.
A root canal is generally required to treat a tooth with pulp necrosis. This involves removing the diseased pulp, disinfecting the root canal chambers, and sealing the space. A crown is recommended afterward to restore full function.
Internal Resorption
Internal root resorption occurs when the body’s cells begin to destroy the internal structure of the tooth. This rare condition creates a hollowed-out area in the dentin and pulp. If allowed to progress, it can lead to loss of the tooth.
On X-rays, internal resorption looks like a round, symmetrical loss of tooth structure. It may appear pinkish-brown if the pulp is still vital, or gray-black if the pulp tissue is necrotic.
Mild cases can be treated with a root canal and filling material to reinforce the tooth. However, severely compromised teeth may eventually require extraction. Early detection provides the best chance of saving the tooth.
Dental Trauma
Traumatic injuries to teeth can cause immediate discoloration along with other types of damage. Accidents like sports collisions, fights, falls, and car crashes frequently cause teeth to become darkened or blackened when injured.
Possible causes of tooth blackening due to trauma include:
- Death of pulp tissue
- Bruising from blood vessels ruptured inside the tooth
- Fracture of enamel allowing dentin to show through
Minor black spots due to trauma may fade over time as the tooth heals. More severe darkening or pulp death will require root canal treatment. Restorations like veneers or crowns can mask any lingering discoloration after repairing the tooth.
Tooth Grinding/Clenching
Excessive grinding or clenching of teeth, known as bruxism, can wear down and damage tooth enamel. Loss of enamel eventually exposes the darker dentin material underneath, giving teeth a yellowish-brown tint.
Worn and flattened teeth are also symptoms of severe bruxism. Treatment often starts with a nightguard worn over the teeth during sleep to prevent grinding. More severely worn teeth can be restored with dental crowns.
Periodontal Disease
Periodontal (gum) disease causes inflammation and destruction of the gums and supporting structures of the teeth. As the condition worsens, it enables more bacterial toxins to enter the teeth themselves.
Severe gum disease can cause the edges of the teeth at the gumline to appear brown. This happens when toxins start to break down the tooth structure and cause decay. Proper treatment of gum disease includes deep cleanings, antibiotics, and sometimes surgery on damaged gums.
Tobacco Staining
Smoking cigarettes, cigars, pipes, chewing tobacco, and other tobacco products can stain teeth from yellowish-brown to nearly black. Tobacco contains chromogens – substances that attach to the enamel and dentin, causing stubborn stains.
Tobacco stains often form in the “nicotine pockets” of the mouth like between and behind the teeth. Heavy smokers can experience extensive brown tobacco staining over many teeth.
Quitting tobacco use prevents further discoloration, though it may not completely brighten teeth already stained. Professional whitening treatments are often needed to actively lift tobacco stains after quitting smoking.
Foods/Beverages
Heavy consumption of certain staining foods and beverages can promote gradual browning and discoloration of tooth enamel. This includes:
- Coffee
- Tea
- Red wine
- Cola
- Dark berries like blueberries
- Sauces and gravies
- Soy sauce
- Balsamic vinegar
The chromogens in these items can penetrate the microscopic enamel cracks and slowly change the shade. Minimizing consumption of staining foods/drinks can help slow further discoloration. Professional whitening can remove superficial staining from the enamel surface.
Aging
As we get older, the outer layer of enamel naturally becomes thinner, allowing the yellowish dentin underneath to show through. This causes teeth to darken slightly and take on a less bright white shade.
Enamel also wears down through many years of chewing and tooth grinding. This thinner enamel transmits more of the color of the dentin. Aging also brings a greater chance of chipping and cracking that can expose darker inner tooth layers.
Routine professional teeth cleanings and daily brushing/flossing will help maintain enamel thickness. Whitening toothpastes or professional whitening can help brighten aging teeth. Restorations like veneers may be indicated for badly worn/damaged teeth.
Congenital Conditions
Some babies are born with congenital conditions that affect tooth color and development. Brown or discolored teeth present at birth may indicate a disorder like:
- Enamel hypoplasia – underdeveloped enamel
- Dentinogenesis imperfecta – defective dentin
- Alkaptonuria – rare disorder causing dark urine and brown teeth
Consulting a pediatric dentist allows early diagnosis of any developmental dental conditions. Proper treatment can then be initiated to help protect oral health and appearance.
Conclusion
Brown tooth discoloration in adults and children can stem from an array of causes. These include health conditions affecting tooth structure, side effects of medications, lifestyle factors, and trauma. In some cases, the brown hue may be a sign of underlying decay or infection needing treatment.
Anyone experiencing a persistent tooth color change should be evaluated by a dentist. They can determine if the cause requires medical or dental intervention. Cosmetic options like professional whitening, veneers, bonding, and crowns can often significantly improve the look of brown-stained teeth when structural health is restored.