On its own, tooth discoloration isn’t harmful — though some of its root causes might be. For most adults, the real concern is how a dull smile makes them feel. From closed-lip smiles to being afraid to lead conversations at work, if you don’t love your smile, it can hold you back.
But the causes of discoloration are diverse, and you’re probably wondering if they’re reversible or preventable. Good news: many are. Keep reading for an in-depth look at the most common causes, plus what you can do to avoid or treat them.
Table of Contents
Types of Tooth Discoloration
There are many causes of tooth discoloration, but most fall into one of three major categories: intrinsic, extrinsic, and age-related. Let’s break down each type.
Intrinsic
Intrinsic stains occur deep inside the tooth below the enamel in the tooth’s dentin. Tooth trauma or serious illness during tooth formation — such as a high, prolonged fever during infancy — are possible causes. Even the way our bodies absorb and process certain medicines can cause these stains.
Extrinsic
As you’ve probably guessed, extrinsic stains come from an external force, like smoking or drinking coffee. Teeth are porous, so extrinsic stains can either sit on the surface or penetrate deeper into the enamel. This is the type of discoloration most people think of when they hear “stained teeth.”
Age-Related
As our bodies age, so does our tooth enamel. Over time, our enamel thins, allowing the darker dentin beneath to show through. Our dentin, which makes up most of a tooth’s structure, is usually a pale yellow. Enamel can wear down from decades of brushing or general wear and tear, and as it does, that yellow color gets more prominent.
Common Causes of Tooth Discoloration
These are the culprits, the catalysts, the most common causes of intrinsic, extrinsic, and age-related tooth discoloration. But we can do more than simply shake our fists at them — we’ll also discuss treatment options for each cause that can help you regain your bright smile.
Food and Drink Stains
Despite being the hardest substance in the human body, tooth enamel is porous and susceptible to stains from certain foods and drinks.
Berries, tomato-based foods, coffee, tea, beets, and red wine all contribute to extrinsic stains on your teeth. Many of the most tooth-staining foods are also full of antioxidants and nutrients, so you might not want to cut them out entirely. Just try to limit them and rinse your mouth with water (or brush your teeth) after consuming them.
Fluorosis
Fluorosis is an intrinsic stain that occurs when a baby or child ingests too much fluoride over a long period when teeth are still forming under the gums. This typically happens before a child turns eight and shows up as white spots, often on the edge of the tooth’s biting surface. Fluorosis can stem from having too many sources of fluoride or by having too much of one source — like fluoride tablets when a town’s water supply isn’t already fluoridated.
Fluorosis can also occur in a child under two who ingests too much fluoridated toothpaste. Check with your child’s dentist to see if they should use toothpaste with fluoride. According to this article by the CDC, children ages two to six can use fluoridated toothpaste as long as they use an amount smaller than a pea.
Medications
As amazing as modern medicine can be, sometimes it can come with side effects, including tooth discoloration. A few of the medicines that might discolor your teeth are:
Chlorhexidine: Chlorhexidine is an antibacterial mouth rinse often prescribed for patients with gingivitis, the beginning stage of gum disease. Sometimes dentists give it to patients after a planing and root scaling procedure to help keep the mouth clean until the gum tissue can heal. However, some patients find it leaves behind extrinsic brown stains.
Antibiotics: Some antibiotics (most commonly tetracycline) can cause stains. Staining from tetracycline happens when a baby or child’s tooth develops under the gum. These stains are intrinsic and become part of the tooth structure itself, causing the teeth to take on a translucent gray appearance.
Antihistamines, Antipsychotics, and High Blood Pressure Medicines: As beneficial as each of these medications can be for our physical and mental health, prolonged use can cause extrinsic stains. How? They can each reduce saliva flow, throwing off your oral pH and making your mouth more welcoming for bad bacteria.
Saliva neutralizes acids and helps bring your oral pH back to neutral, but when you can’t make enough, it upsets this delicate balance and allows stains to stick to your teeth. Saliva is also your body’s way of rinsing away food particles. With little to no saliva, food particles can stick to the teeth, depositing stains.
Broken or Damaged Fillings
Even though composite (white) fillings on your back teeth are becoming increasingly common, some insurance plans still won’t cover them, or will downgrade the coverage to an amalgam (silver) filling. Depending on a silver filling’s size and proximity to the enamel’s surface, it may leave a gray shadow that’s visible when you smile.
Also, over time, an amalgam filling will break down and start to oxidize, turning from silver to black. When this happens, the filling can shrink and allow bacteria to penetrate the tooth, causing decay. This is one reason regular dental visits with X-rays are important.
Decay can hide underneath a filling and eat at the tooth from the inside. Once this happens, there may not be enough tooth structure to insert a filling, and you may need a more complicated (and costly) restoration to save your tooth.
White composite resin fillings may not oxidize or cast a gray shadow, but they can still cause intrinsic discoloration. The surface of a resin filling can discolor over time, and if you have an older composite filling, the edges can become rough or chipped from normal wear and tear. The filling’s edge, called the margin, can catch food and drink particles and become discolored.
This rough edge also traps bacteria, and much like an amalgam restoration, decay can creep in and flourish underneath the filling. X-rays can catch decay that isn’t visible to the naked eye, and your dentist or hygienist can perform an exam under magnification to detect any suspicious areas while they are still small.
Thin Enamel
As much as we might try to prolong our youth, time doesn’t slow down, and age affects everyone. Decades of wear and tear cause the enamel to thin, letting the dentin underneath show through. Unfortunately, as we age, our dentin also gets larger, reducing the size of the pulp or nerve in a tooth. This means that an otherwise healthy tooth is more likely to look yellow with age.
Eating foods high in citric acid, drinking soda daily, regular vomiting, clenching and grinding your teeth, and acid reflux can also wear down your enamel.
Tobacco Use
Nicotine — whether from cigarettes, chewing tobacco, or tobaccoless products like vape juice — is a highly addictive substance. Not only does it cause a laundry list of health problems, but it can also stain your teeth. Nicotine turns brown when exposed to oxygen, turning your teeth (and fingernails) yellow.
Cigarettes also contain tar, another tooth-staining culprit. Combined, nicotine and tar leave behind extrinsic stains from a sticky residue that adheres to your teeth and other surfaces, including the lining of your lungs. Quitting smoking helps keep your teeth white and also reduces your risk of developing periodontal disease, which can cause bone and tooth loss if left untreated.
Trauma
Trauma to a tooth causes an intrinsic discoloration that brushing and professional cleaning can’t remove. This can occur due to health issues in early childhood or injuries at any point in life.
A high fever can throw off the balance of calcium and proteins present in developing teeth during infancy and young childhood, causing discoloration. This usually occurs during early tooth formation in children younger than eight years old.
Other common causes of childhood tooth discoloration are illnesses like newborn jaundice, newborn hepatitis, undiagnosed celiac disease, congenital heart conditions, and even recurrent infections. The discoloration can affect the whole tooth or just parts, and it can extend to just a few teeth or an entire arch.
A blow to the face or a fall can cause a tooth to turn dark gray. This change in color indicates that the tooth isn’t receiving enough blood. The pulp, or nerve, may be inflamed or even dying. If it’s inflamed, the swelling inside the tooth might subside and eventually return to its normal color. If the nerve is dying or has died, the tooth may be permanently discolored.
Later Childhood and Adulthood Illness
Illnesses like liver disease, sickle cell disease, rickets, and celiac disease can present themselves physically as darkened dentin, an intrinsic discoloration that gives teeth a yellowish hue.
Calcium and vitamin D deficiencies might also cause intrinsically discolored teeth. As the deficiency worsens, your body takes calcium and vitamin D from the stores in your teeth and bones and gives it to areas that need more help. Over time, this thins your enamel and allows your dentin to show through.
Tooth discoloration can also result from certain treatments, particularly chemotherapy. Dry mouth is a common side effect of chemotherapy, and just like with certain medications, this saliva deficiency throws off your natural oral pH, making your mouth more welcoming to bad bacteria. Plus, when saliva can’t wash away food particles, they can stick to the teeth, causing stains. Discoloration from chemotherapy is often extrinsic.
Poor Oral Hygiene
Brushing and flossing twice a day and seeing your dentist for professional cleanings keep your teeth and gums healthy, but it also prevents stains that can cause extrinsic discoloration. Regular checkups remove the built-up stains, plaque, and tartar. Unremoved plaque is sticky and hardens into tartar, which is rough. Both are stain magnets, and if you don’t remove them, they can become impossible to treat with at-home care.
Skipping a dental cleaning or not keeping your teeth clean between professional cleanings allows tartar build-up, potentially causing gingivitis and periodontal disease that can lead to bone and tooth loss.
Pregnancy
Pregnancy can be very hard on your body; its many side effects can include dental issues and tooth discoloration.
Morning sickness, one of the most common pregnancy symptoms, can wear down the tooth enamel, allowing the dentin to show through as intrinsic tooth discoloration. And iron supplements — commonly recommended during pregnancy — can also leave extrinsic stains. Further, if a mother takes tetracycline during pregnancy, it can discolor the baby’s teeth because their teeth develop below the gums before birth.
Is Tooth Discoloration a Health Concern?
Tooth discoloration can be just an annoying cosmetic issue that makes you want to smile with your mouth closed, but it can also signify underlying health problems that may or may not have manifested in other ways.
Even if they seem minor, pay attention to changes in your mouth. If you notice any, notify your dentist and physician, especially if you haven’t changed the way you eat, the frequency or quality of your homecare routine, or the regularity of professional cleanings.
What Can I Do About Tooth Discoloration?
Now that we’ve explored some common causes of discoloration, we can discuss how to treat and even prevent it.
Schedule a Professional Cleaning
If you haven’t had a professional cleaning in a while, it’s the best place to start treating extrinsic stains and discoloration. Your teeth and gums thank you for removing the built-up plaque and calculus, plus you’ll get a professional exam to check for gum disease, tooth decay, and oral cancer.
Veneers
If you have deep, intrinsic stains from fluorosis, chlorhexidine use, or an injury, veneers can be a great way to cover them up. Veneers are also an option if you have thin enamel but an otherwise healthy tooth.
Veneers can be porcelain, ceramic, or a composite resin material like the kind used for white fillings. They’re a thin covering that a dentist either cements over your existing tooth or bonds directly to it. Veneers can reshape a crooked or misshapen tooth, or they can replicate your existing tooth so no one will ever know.
External Teeth Whitening
Professional cleanings can’t completely eliminate every stain, especially if it’s been years since your last office visit. The more time that passes, the deeper these stains penetrate the enamel. Luckily, you can whiten your teeth to remove those lingering stains and get your smile sparkling again!
For anyone who’s short on time or wants amazing results in one visit, an in-office professional whitening treatment can remove years of staining in around one hour. This method is also great for people with age-related thinning because the whitening gel’s professional strength can penetrate the enamel. Just be careful that your dentist uses a concentration made for patients with sensitive teeth because people with thinner enamel have a greater risk of developing sensitivity.
Suppose you would rather whiten your teeth from the comfort of your own home or break the whitening experience into smaller sessions. In that case, your dentist can provide take-home trays custom-made from impressions of your teeth, or you can purchase over-the-counter whitening trays, whitening strips, or whitening pens. These products are typically less concentrated and gentler for people with thin enamel, though their results tend to be less dramatic than in-office options.
Internal Bleaching
A tooth that’s discolored from a dead nerve may not respond to external whitening, but your dentist can perform internal bleaching instead. Dentists typically reserve this method for teeth with root canals but enough preserved tooth structure that they don’t need crowns. They’ll soak a small piece of cotton in a whitening agent, place it inside the tooth from the back, and seal it with a temporary filling material. This may take a visit or two, but once the tooth matches your other teeth, your dentist will remove the cotton and put in a permanent filling.
Replace Your Amalgam Fillings
Changing your amalgam fillings for white composite fillings can eliminate the silver shadow. But if your amalgam fillings are large or have turned the tooth itself gray, your dentist may not recommend a simple filling swap.
Crowns
For people with large, oxidized silver fillings that have discolored a tooth, your dentist may recommend a crown to preserve what’s left of the tooth structure. Crowns can be a gold alloy, porcelain fused to gold or silver, or a ceramic material made in your dentist’s office. They fit over your existing tooth and are cemented into place.
Final Thoughts
The first step in addressing tooth discoloration is understanding the causes behind it. Once you know why your smile isn’t as bright as it once was, you can work on correcting these issues and finding the correct treatments for your smile. If you aren’t sure why your teeth are discolored, speak with a dental professional for guidance.
Frequently Asked Questions
What are intrinsic stains?
Intrinsic stains occur deep within the tooth, often from a specific medication or a high fever during childhood.
What are extrinsic stains?
Extrinsic stains sit on the surfaces of your teeth and can result from medicines, foods, and tobacco use.
What is age-related tooth discoloration?
As we age, the layer under our enamel, called dentin, gets larger and more yellow. At the same time, our enamel starts getting thinner. Thinning enamel lets the yellowed dentin show through, making your teeth appear discolored.
Can I avoid tooth discoloration?
Sort of. You can limit tooth-staining foods, rinse after meals, and quit smoking, but some forms of tooth discoloration are unavoidable.
How do I fix my tooth discoloration?
It depends on the type of discoloration. Sometimes a professional cleaning or whitening session will do the trick, but some stains require a more intensive solution, like a crown.
Does tooth discoloration hurt?
Unless your discoloration is from thinning enamel that also causes sensitivity, tooth discoloration shouldn’t hurt at all.
How do I find out if my medicine causes tooth discoloration?
Most medicines come with a package insert that lists all the possible side effects. If yours doesn’t, check with your physician or pharmacist.
Is it too late to fix my tooth discoloration?
It’s never too late to fix your discolored tooth or teeth! Consult your dentist to find out which might be the best treatment for you.
Will insurance cover the cost to fix my discolored tooth or teeth?
Maybe! Most insurance plans will cover crowns or veneers, and some plans cover internal bleaching for a single tooth. They won’t, however, cover in-office whitening and at-home whitening since those are cosmetic procedures.
Can tooth discoloration come back?
Unfortunately, yes. Taking a new medicine or enjoying heavily pigmented foods and drinks will cause discoloration to return.
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