Dark Teeth


Several conditions can change the color of a tooth, from light yellow to dark brown or grey. They are usually divided into three main categories:

  • Extrinsic: staining occurs on the outer layer of the teeth. Extrinsic staining is typically caused by tea, coffee, smoking or wine.
  • Intrinsic: staining occurs inside the tooth through darkening of its internal structures. Several conditions can cause intrinsic staining, including:
    • Exposure to high amounts of fluoride during childhood
    • Use of the antibiotic tetracycline at young age
    • Dental trauma as a child or adult
    • Root canal treatment
    • Rare genetic conditions such as dentinogenesis imperfecta
  • Age-related: with aging, the dentin of the tooth (inner part of the tooth) gets more yellow and the enamel (outer layer of the tooth) gets thinner and more transparent, thus showing through the yellow of the dentin. Extrinsic staining can make the condition worse.



In most cases, tooth discoloration is a cosmetic problem and do not affect oral health. A clinical examination combined with the history of the staining is normally enough for the dentist to establish a diagnosis.

Staining due to extrinsic factors typically requires professional dental cleaning and polishing and adequate daily oral hygiene. Stronger extrinsic stains might need dental bleaching.

Intrinsic staining can require different treatment options according to the case. Internal and external bleaching are normally the first choices. Internal bleaching requires the dentist to place a bleaching agent inside the tooth. External bleaching can be done at home, using trays to deliver a bleaching solution, or at the dentist through application of a light-activated gel.

It is important to notice that dental restorations (fillings, crowns, veneers, bridges, ect.) are not bleached; hence, they will look darker in relation to bleached teeth and will require replacement.

Home bleaching with over the counter products is not recommended. The trays need to be custom-made and the bleaching process needs monitoring to avoid damage.

Whitening toothpastes can only remove minor external staining. Dark tooth discolorations can require dental crowns or veneers.



A bad bite alone cannot make teeth darker, but its consequences can result in darker teeth and in other serious health consequences.

An improper bite results in unbalanced distribution of biting pressure, thus subjecting some areas to intense forces. This can cause the enamel to develop thin crack lines. Over time, these lines (called craze lines) can get stains from the food, becoming noticeable.

A bad bite can also make teeth look darker is when there is tooth wear due to tooth grinding. Many people with an improper bite tend to grind their teeth during the night, as an unconscious attempt to grind away the interferences. For hours, teeth are subjected to excessive forces, which can cause craze lines and enamel wear.

While enamel is transparent, the underlying dentin is yellow. The thinner the enamel, the more of the yellow dentin is seen; thus, worn out teeth look darker.

When there is a bad bite component to a dark smile, bleaching can help improve appearance, however, the most important part is the correction of the bite to prevent more problems.



While most people would consider bleaching, orthodontic treatment can sound overwhelming for many adults who need correction for their bite issues. Clear aligner therapy, such as Invisalign, can completely correct the position of the teeth and jaws, improving function and appearance at the same time.

They are conveniently designed to slowly shift teeth through thin plastic devices, which are removable. Hence, daily activities are not affected and the devices are barely noticeable. This is possible through computer programs and advanced technology, developed exclusively for orthodontic treatment.

Improve the appearance and function of your teeth for long-term health benefits.