Black Triangles Between Teeth – Why they happen and what to do about it

Black Triangles Between Teeth – Why they happen and what to do about it

When it comes to a perfect smile, beautiful white teeth, perfectly aligned with no stains, grab all the eyes. However, not everyone is blessed with them naturally. One or the other dental imperfection creates a nuisance, and here we are talking about black Triangles between the teeth– one of the common dental issues. 

What to Know About Black Triangles?

Black Triangles Between Teeth

Black appearance in between the teeth, also called black triangles, are the dark spaces at the gum line. According to a study, it is one of the most identified aesthetic complaints (1). 

They are the small gaps that form between the teeth and gum line. In medical terms, black in between the teeth is termed as gingival embrasures that are commonly found in the front teeth. The major reason behind their occurrence is the lack of gum tissues. These gaps are usually triangles in shape, thus named black triangles.

Besides reducing the aesthetic appeal of the mouth and making the smile less attractive, black in between the teeth can also lead to serious dental problems when left untreated. 

What Causes Black Triangles Between Teeth?

Black between the teeth or black triangles may result due to many reasons. Mostly, they form as a result of some underlying issues with the gums, where in gum recession is considered the major factor. 

As we age, the gum recedes, and when it combines with other dental problems like gum disease, dental infection, or vigorous brushing, the problem of gingival embrasure comes up. The triangle-shaped gaps start becoming prominent, impacting the perfect smile you always had. 

Additionally, they usually appear on incisors- the front teeth in the mouth. When the teeth in the pores are narrower at the gum line than at the biting surface, the chances of getting black gaps increase with age due to gum recession. 

Over time, the gums no longer occupy these gaps between the teeth, leading to vacant spaces that resemble black triangles. 

Let’s take a look into the major causes of gingival embrasure.

1. Gum recession 

Healthy gums are plump and pink, hug the teeth, and fill the spaces surrounding the teeth. However, as we age, the gum starts receding or pulling away from the teeth, exposing the roots of the teeth and making them vulnerable to cavities and infections. Besides age, smoking is another reason why gum starts receding early and making the teeth sensitive. 

2. Brushing aggressively

Brushing aggressively

Using hard brushes, scrubbing teeth aggressively, and flossing too hard are some common incorrect dental hygiene practices that people exercise. Since the gum tissues are sensitive, they are prone to damage easily, and aggressive daily brushing hampers their health over time (2). 

As the gum is damaged, it creates gaps between the teeth, making their roots exposed and food easily trapped, deteriorating overall dental health. Therefore, learning the right tooth brushing practice is essential. 

3. Bone Loss

Gum is prone to infections, and this condition is called periodontitis. In this condition, the bone starts dissolving under the gums. As the infection triggers, the immune response starts functioning constantly. While in some cases, the infection resolves, in others, the bacteria hide deep under the gums and never leave.

In such cases, the bone is lost, and the gum starts leaving the teeth, leading to the appearance of blackness between teeth. Besides this, problems like osteoporosis and severe gum diseases also cause bone loss. 

4. Orthodontic treatment

People who have undergone any orthodontic treatment to align their teeth, such as braces, clear aligners, and removable retainers, may face black triangles later in their lives (3). 

Even though these treatments are intended to straighten the teeth and efforts are made to move them to a new position to look better and aligned, the changes may leave gaps between the teeth. In such cases, further treatment is required to fill in these black gaps. 

5. Triangular tooth shape

Another cause of black between teeth is the teeth’s shape. People with narrower teeth at the gum line are more susceptible to getting black triangle problems with age. 

As soon the gum starts receding over time, the gaps start becoming more prominent in narrower or triangular teeth because such teeth have more space between the contact and gum tissues.

On the contrary, in rectangular teeth, wherein the width of teeth in the gumline is almost the same as the width of the tooth edge, the black triangle does not become prominent. This is because such teeth have very small spaces between them to be filled by the gum tissues. 

6. Thin fragile gum tissue 

The thickness of gum tissues is different in every person. If these tissues are thin and fragile, they are more susceptible to damage, especially when a person gets gum disease, dental treatment, or gum surgery. In such cases, the fragile and thin gum tissues are damaged to some extent, and it is irreversible damage, leading to the black triangle. 

Therefore, people with thin and fragile gum tissues should stay more cautious of their dental health and practice the right dental hygiene using soft brushes to maintain their health and vitality. 

Is Black Triangles Between Teeth Concerning?

Black between the teeth is not appealing aesthetically, which is one of the reasons why people don’t like them. At the same time, the gaps can trap the food particles easily, making teeth susceptible to cavities, damage, tooth decay, and gum diseases. Moreover, the roots of teeth get exposed, again making them sensitive and susceptible to various dental issues. 

Therefore, it is advised to seek medical help if you witness blackness between the teeth to avoid future uncertainties pertaining to dental health. When treated correctly, the problem of the black triangle reduces, giving back your beautiful smile all over again. 

How to Prevent Black Triangles Between the Teeth?

The chances of preventing black between teeth are less among people with narrow teeth. However, they can still make efforts to keep their dental and oral health perfect to avoid the problem later. The same goes for others because, with a good daily oral care routine, a lot of dental issues like gum diseases and infections can be avoided. 

  • Brush gently, preferably twice a day
  • Use brushes with soft bristles
  • Floss gently once a day (4)
  • Watch out for swollen or red gums and loose teeth 
  • Seek medical help if toothache is severe


Black in between teeth is not aesthetically attractive; however, efforts can be made to reduce the chances of getting them by practicing the right dental and oral hygiene. Now that we know what the causes behind blackness between the teeth are and how to prevent the condition, it’s high time to look into the mirror and start working on the dental imperfections. 

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