Having yellow teeth can be embarrassing and make you feel self-conscious about smiling or laughing. While many factors can cause teeth discoloration, it often occurs first or most noticeably on the back teeth. Understanding what causes back teeth to turn yellow is the first step to whitening your smile.
What Causes Yellow Teeth?
There are several potential causes of yellow teeth:
- Food and Drink Stains: Dark colored foods and drinks like coffee, tea, red wine, and berries can stain the enamel on your teeth over time, especially if you consume them frequently.
- Tobacco Use: Using tobacco products like cigarettes and chewing tobacco exposes teeth to tar and nicotine, which cause yellow-brown stains.
- Poor Oral Hygiene: Not brushing and flossing thoroughly allows plaque – a sticky film of bacteria – to build up on your teeth and harden into tartar. This can contribute to stains.
- Genetics: Some people naturally have thinner enamel or enamel with a yellowish tint that makes teeth appear less white.
- Medications: Certain prescription drugs like tetracycline antibiotics taken while teeth are developing can cause permanent tooth discoloration.
- Fluorosis: Consuming excess fluoride while teeth are forming can lead to tiny white specks or streaks called fluorosis.
- Aging: Over time, enamel wears thin and the inner dentin layer shows through more. Dentin has a natural yellowish hue.
Why Back Teeth Turn Yellow First
The back teeth – molars and premolars – tend to show yellowing and staining most noticeably for several reasons:
- Less Visibility – Front teeth are more visible when smiling and talking, so most people focus more effort brushing and whitening them.
- Flatter Surfaces – Back teeth have broader, flatter outer surfaces which allow stain-causing particles to adhere more easily.
- Grooves and Crevasses – Back teeth have chewing surfaces covered in pits and fissures that allow stains to penetrate deeper.
- More Plaque Buildup – It’s harder to reach molars thoroughly when brushing, allowing more plaque to accumulate.
- Less Enamel – Molars have naturally thinner enamel than front teeth, making stains more apparent.
- Location – Saliva flows towards the back of the mouth, carrying stains with it.
Additionally, back teeth tend to show age-related yellowing sooner since their thinner enamel wears faster over time, revealing the yellowish dentin underneath.
Foods and Drinks That Stain Back Teeth
Certain foods and beverages are more likely to cause stains on back teeth. Common culprits include:
- Coffee and tea
- Cola and dark sodas
- Red or purple grapes and berries
- Tomato sauce and ketchup
- Curries and saffron
- Beetroot
- Red wine
- Soy sauce
These foods and drinks contain pigments that can adhere to tooth enamel or seep into tiny grooves and fissures. Acidic drinks like coffee and soda also erode and thin enamel over time, making stains more noticeable.
Tobacco and Back Tooth Staining
Smoking cigarettes, cigars, pipes and chewing tobacco all expose teeth to tar and nicotine, which cause stubborn brownish stains. The intensity of staining depends on how frequently and long you use tobacco products.
Like with foods, tobacco smoke tends to stain the back teeth most due to:
- More surface area for toxins to stick
- Harder to brush thoroughly
- Increased plaque due to irritation of gum tissue
Using tobacco for extended periods can lead to permanent discoloration as the tar penetrates deep into pores in the enamel. Quitting tobacco use can prevent worsening stains but may not eliminate those already present.
Plaque and Tartar Buildup
Plaque is a sticky film of bacteria, food debris and saliva that coats teeth after eating or drinking. If not removed promptly by brushing and flossing, plaque hardens into tartar which adheres firmly to teeth, providing an ideal base for stains to affix.
Molars and premolars tend to accumulate more plaque and tartar since they are harder to keep clean. The grooves and pits on chewing surfaces also provide plenty of nooks for plaque to gather.
A buildup of tartar causes teeth to look dull and yellow. Only a professional dental cleaning can fully remove tartar deposits.
Medications That Stain Teeth
Certain prescription medications can cause tooth discoloration, especially if taken by children while their teeth are still developing. Common culprits include:
- Tetracycline antibiotics
- Antihistamines
- High blood pressure medications
- Anti-depressants
Medication-induced tooth staining is difficult to remove through typical whitening methods. However, avoiding these medications once teeth are fully formed can prevent additional discoloration.
Preventing Yellow Back Teeth
You can help keep your back teeth their whitest by:
- Brushing thoroughly twice a day for 2 minutes, paying extra attention to back teeth
- Flossing daily to remove plaque from between teeth
- Getting regular professional cleanings every 6 months
- Avoiding frequent snacking and sipping acidic or sugary foods and drinks
- Drinking staining beverages through a straw to minimize contact with teeth
- Rinsing mouth with water after consuming staining foods and drinks
- Quitting tobacco use
While diligent oral hygiene may slow discoloration, nearly everyone will eventually develop some degree of yellowing, especially on molars. When this occurs, various whitening techniques can help remove stains.
Whitening Options for Yellow Back Teeth
If you notice your back teeth growing more yellow, discuss these whitening options with your dentist:
- Over-the-counter whitening strips or gels – Apply to teeth for 30-60 minutes 1-2 times per day until desired shade is reached.
- Dentist-provided in-office whitening – Uses a hydrogen peroxide gel and special light to swiftly whiten teeth in one 60-90 minute visit.
- Custom-fitted take-home whitening trays – Wear peroxide-based gel in trays molded specifically for your teeth 1-2 hours per day or overnight.
- Professional strength whitening toothpastes – Contain polishing agents and higher peroxide concentrations to boost brightness with regular brushing.
Keep in mind whitening treatments only remove surface stains, not inner discoloration. Results also vary based on the original shade of your teeth, with yellow teeth whitening better than grey or brown stained teeth.
When to See a Dentist
Consult your dentist promptly if you notice:
- Sudden or rapidly worsening tooth discoloration
- Yellow spots or patches on only some teeth
- Stains along the gumline
- Sensitivity or pain when consuming hot, cold or sugary foods
These signs could indicate an underlying dental health issue needing treatment, rather than purely cosmetic stains. Schedule a checkup at least every 6 months so your dentist can monitor for problems and recommend appropriate whitening methods.
Conclusion
A variety of factors can cause yellow discoloration of teeth, especially back molars and premolars. Stains from food and drinks, poor oral hygiene, tobacco use, medications and aging are common culprits. Molars tend to show yellowing sooner due to their position, flatter surfaces and natural thinner enamel.
While some yellowing is inevitable with age, limiting staining culprits and maintaining thorough oral hygiene can prolong a bright smile. If discoloration does occur, several safe and effective whitening options are available to remove surface stains for a rejuvenated white smile.