Why Do Teeth Turn Yellow?
While celebrities and models have pearly white teeth, most people’s smile is a bit more boring. That shouldn’t be too surprising, though. Many things can affect the color of your teeth, turning them the dreaded yellow hue, which can make some people feel apprehensive about their appearance and be reluctant to smile.
An abnormal tooth color is considered to be any color other than white or yellow-white, according to the US National Library of Medicine.
Most causes of tooth discoloration fall into two main categories: extrinsic and intrinsic stains. Yellowing can also be caused by a variety of health factors, from medication use to inadequate brushing.
Extrinsic stains affect the surface of tooth enamel, which is the hard, outermost layer of teeth. Although tooth enamel can be easily stained, these stains can typically be removed or corrected.
“The number one cause of tooth yellowing is lifestyle,” said Dr. Justin Philipp from J. Philipp Dentistry in Chandler, Arizona. “Smoking, drinking coffee and tea, and chewing tobacco are the worst offenders.”
The tar and nicotine in tobacco are chemicals that can cause yellowish stains on the surface of teeth in people who smoke or chew.
As a rule of thumb, any food or drink that can stain clothing can stain your teeth as well. This is why dark foods and drinks such as red wine, cola, chocolate and dark sauces such as soy sauce, balsamic vinegar, spaghetti sauce and curries can stain teeth. In addition, some fruits and vegetables such as grapes, blueberries, cherries, beets, and pomegranates can stain teeth. These products are rich in chromogens, pigment-producing substances that can stick to tooth enamel. Popsicles and candy are other foods that can stain teeth.
Acidic foods and beverages can promote discoloration by removing tooth enamel and making pigments easier to stick to teeth. Tannin, a bitter compound found in wine and tea, also helps chromogens to build up on tooth enamel, which ultimately leads to staining. But there is good news for tea drinkers: A 2014 study published in the International Journal of Dental Hygiene found that adding milk to tea reduced the chances of tooth discoloration because the proteins in the milk can bind to tannin.
Liquid forms of iron supplements can stain teeth, but there are several ways you can prevent or remove these stains, according to the Mayo Clinic.
If the teeth are not being properly cared for, e.g. Inadequate brushing and flossing, and failure to clean your teeth regularly can prevent stain-causing substances from being removed and lead to plaque build-up on teeth, resulting in discoloration.
Intrinsic stains appear in the internal structure of the tooth called the dentin, making these stains more difficult to remove.
Numerous medications can cause intrinsic stains on teeth. If children take the antibiotics tetracycline or doxycycline while their teeth are still developing (before the age of 8), their teeth may turn brownish-yellow. Women who take tetracycline after the fourth month of pregnancy or while breastfeeding can cause a child to have discolored milk teeth, according to the Mayo Clinic.
In adulthood, using prescription mouthwash that contains chlorhexidine, a compound that can reduce bacteria and treat inflammation of the gums (gingivitis), can cause brown discoloration of teeth. In addition, the acne-fighting drug minocycline, a derivative of tetracycline, stains teeth.
Chemotherapy treatments, as well as radiation to the head and neck, can lead to intrinsic spots. Even some relatively common medications, such as antihistamines, antipsychotics, and blood pressure medications, can sometimes turn teeth yellow.
Although fluoride can be beneficial for teeth by strengthening tooth enamel and preventing tooth decay, ingesting too much mineral is not good for tooth color. Fluorosis, which results from excessive amounts of fluoride, can cause faint white streaks or brown stains on teeth. According to Philipp, this is especially a problem in areas where the drinking water contains a high proportion of naturally occurring fluoride, for example in areas where people get their water from wells. It’s also possible to get too much fluoride from taking supplements or regularly using conditioners and toothpastes with the mineral in them.
Dental treatments can also cause teeth to darken. “Many dental materials can cause discoloration, especially amalgam restorations (silver fillings),” said Dr. Bruno Sharp from Sharp Dentistry in Miami, Florida. According to The Cleveland Clinic, these can give the tooth a gray-black sheen.
In addition to stains, genetics, age, disease, and injuries are some other causes of discolored teeth.
There are many reasons some people are more likely to have a yellow tint on their teeth, said Dr. Edita Outericka, the dental director at Dynamic Dental in Mansfield, Massachusetts. “The main reason is genetics. Dentinogenesis imperfecta and Amelogenesis imperfecta are two inherited diseases that prevent teeth from developing properly and can lead to discoloration,” Outericka explained.
Heredity is also the reason why some people naturally have lighter or thicker enamel than others. You can simply be born with teeth that appear more yellow (or whiter) compared to other people’s teeth, Outericka said. Part of it has to do with the thickness of your tooth enamel, which is semi-transparent. When you have a thin layer of enamel, the true color of your naturally yellowish dentin will show through.
Age can darken the color of your teeth: as you age, the outer layer of enamel becomes thinner and the teeth appear more yellow. The best protection against enamel thinning, according to the Mayo Clinic, is to ensure proper saliva production, which can wash food and plaque off your teeth and retain adequate fluoride. Brush with a fluoridated toothpaste twice a day, drink fluoride treated water, and see a doctor if you have a dry mouth to keep your enamel from thinning.
The color of your teeth can also be affected by disease. Yellowing may occur if there is a high fever from an infection at a young age. Severe jaundice in newborns is another possible cause of yellowing of the teeth, according to Outericka.
Falls or sports injuries in young children can disrupt tooth enamel if the children’s permanent teeth are still developing and result in a grayish appearance. Similar injuries that damage nerves or chip teeth in adults can also discolour permanent teeth. In addition, people who frequently grind their teeth excessively during sleep can slowly remove the outer layer of tooth enamel, exposing the yellowish dentin underneath.
Prevention & Treatment
The best prevention against yellow teeth is to be careful what you eat and drink, and not to smoke. You should also practice good dental hygiene and see a dentist at least twice a year.
The easiest cause of yellowed teeth to repair is poor oral hygiene: when plaque (a film of bacteria that forms on teeth) and tarter (hardened dental plaque) form, teeth can appear yellow. According to Outericka, removing these debris before tooth decay sets in is critical to a whiter smile and healthy teeth.
“It’s best to have a professional clean your teeth regularly,” said Outericka. “This will help remove stains. Also, drinking through a straw will minimize the time that liquids remain on the surfaces of the teeth,” she noted. You can also rinse your mouth with water after eating food or drink that may cause stains if brushing is not possible.
If you are not satisfied with the color of your teeth, consult a dentist. “There are numerous treatments that can result in a bright white smile!” Said Outericka.
Additional coverage from Cari Kidneyberg and Joseph Castro, Live Science contributors.