Black Triangles in Teeth and Cosmetic Ways to Close Them

A set of straight, white teeth looks great. However, if they are not in harmony with the gums and other oral structures, your smile stays far from perfect. That’s exactly what black triangles in teeth, medically termed open gingival embrasures, do. They totally ruin your smile, no matter how straight or white your teeth are.

So, what are black triangles teeth? How do they form?

This guide will outline interesting information regarding them: their causes, impact, and most effective treatment options, to help you make wise decisions about restoring your smile.

What Is a Black Triangle in Teeth?

A black triangle between teeth refers to the small triangular gap visible between two neighboring teeth. It occurs when the gum tissue (interdental papilla) that usually fills this space is missing or reduced. In dentistry, this condition is called an open gingival embrasure (OGE).

Its appearance and size depend on factors such as tooth shape, gum tissue height, the contact point between teeth, underlying bone levels, and gum thickness.

Why this matters:

• Aesthetic: The dark space disrupts the uniform look of the smile.
• Functional: It can trap food and increase the likelihood of plaque buildup.
• Psychological: It may lower self-confidence and affect social interactions.

Anatomy & the Key Determinants of Papilla Presence

Here’s a breakdown of the anatomy and key determinants of papilla presence:

• Interdental Papilla: The triangular gum tissue that usually fills the gap beneath the contact point of two teeth.
• Alveolar Bone Height: The distance from the bone crest to the tooth contact point is the most critical factor. If this distance is 5 mm or less, the papilla typically fills the space; beyond that, the likelihood decreases.
• Tooth Contact Point and Crown Shape: Teeth with triangular crowns tend to create larger gaps compared to those with square-shaped crowns.
• Gum Tissue Type: Thin, scalloped gums are more prone to recession and papilla loss compared to thick ones.
• Gum Health: Gum disease and inflammation can cause bone loss and shrink papilla volume.

Causes of Black Triangles in Teeth

Black triangles, those small dark gaps that appear between teeth, can result from several different processes. Here are the most common reasons:

Loss of the Interdental Papilla Due to Periodontal Disease

One of the leading causes is gum disease. When the gums are inflamed, they lose their attachment to the tooth, and the bone underneath begins to recede. Since the papilla, the small gum tissue that usually fills the space, depends on bone support, it shrinks when the bone level drops, leaving an open gap. In many cases, chronic periodontitis is the main cause.

Bone Loss (Crestal Resorption)

In cases of vertical bone loss or defects between teeth, the bone support under the gum tissue is no longer sufficient. Without this support, the papilla can’t maintain its natural shape, and the black triangle forms.

Gum Recession (Soft Tissue Recession)

When the gum margin moves downward (or upward in upper teeth), the space between teeth opens up. This can occur from brushing too hard, having naturally thin gums, or sometimes as a result of previous dental surgeries.

Orthodontic Treatment-Related Changes

Moving teeth with braces or clear aligners can create small new gaps between them. Shifting teeth with braces or aligners can sometimes cause new spaces to appear. Movements such as flaring the front teeth forward, roots moving apart, or creating small spaces between teeth can alter where the contact points sit.

This increases the size of the gap. Research has shown that adults undergoing orthodontic treatment may have a higher chance of developing black triangles.

Tooth Shape and Contact Point Position

Not all teeth are shaped the same. Triangular teeth (narrower near the gums and wider at the biting edge) naturally create bigger embrasure spaces compared to square-shaped teeth. If the contact point between two teeth is positioned too high, the papilla doesn’t have enough room to fill in, making a black triangle more likely.

Aging

As we age, our gums naturally recede a little, and our teeth wear down. These changes can cause the gums between the teeth to shrink, creating small triangular spaces that weren’t visible before.

Dental Work (Iatrogenic Factors)

Sometimes, dental treatments themselves can cause or worsen black triangles. For example, crowns that are too bulky, restorations that aren’t finished properly between the teeth, or crown margins that irritate or displace the papilla can all lead to these spaces.

How Clinicians Diagnose Black Triangles?

To properly treat black triangles, dentists first need to identify the exact cause. A detailed evaluation helps guide the right solution. The diagnostic process usually involves several steps:

Medical & Dental History

The dentist reviews the patient’s background, including any history of gum disease, orthodontic treatments, or daily habits such as brushing techniques that may affect the gums.

Clinical Examination

A close look inside the mouth is done to measure the size of the gap (embrasure) and to evaluate gum tissue type, whether it’s thin or thick, and the amount of keratinized (firm) tissue present.

Probing & Periodontal Charting

Using a probe, the dentist checks for gum pockets and measures any loss of attachment, which can indicate gum disease.

Radiographs (X-Rays or CBCT Scans)

Images are taken to measure the bone height between the teeth in relation to where the contact point is. This is a key factor in whether the gum tissue (papilla) can regrow and fill the space.

Study Models & Photographs

Models of the teeth and detailed photos are often used to document tooth shape and how the contacts meet. Wax-ups or digital mock-ups may also be created to plan possible restorative changes.

Contact Point to Bone Crest Distance

This measurement is critical. If the distance from the bone crest to the tooth contact point is 5 mm or less, there’s a good chance the papilla can regenerate and close the gap. If it’s greater than 5 mm, the predictability of papilla regrowth decreases significantly.

Cosmetic Dental Solutions for Gum Gaps

Fortunately, modern dentistry offers a wide range of treatments for gum gaps. The best option depends on the size of the gap, the condition of your gums, and your personal smile goals. Here are several cosmetic dental solutions for gum gaps:

Dental Bonding

Dental bonding to close gaps is one of the simplest and most affordable solutions for black triangles in teeth. In this treatment, a tooth-colored composite resin is carefully applied and sculpted along the sides of your teeth to close the triangular spaces. Bonding is quick, minimally invasive, and cost-effective. However, because the material can wear down or stain over time, touch-ups may occasionally be needed.

Veneers

For patients seeking a stronger and more aesthetic solution, porcelain veneers are an excellent choice. Veneers cover the front surface of the teeth, reshaping them to close the gaps while improving color, length, and symmetry. They provide a natural-looking, durable result. They also work well for hiding white spots on teeth, chipped teeth, or any other minor damage.

However, they are more expensive than bonding and involve teeth shaving that removes a thin layer of enamel.

Orthodontic Treatment

When gum gaps are caused by misaligned or spaced teeth, orthodontics, such as braces or clear aligners , may be the best route. These treatments gradually reposition the teeth, helping to close open gingival embrasures. While orthodontics takes longer than bonding or veneers, it addresses the underlying cause and offers a permanent fix for alignment issues.

Gum Tissue Treatments (Soft Tissue Grafting)

If the gap is due to gum loss, soft tissue grafting may be needed.“This surgical approach rebuilds lost gum tissue, enabling the papilla to regenerate and naturally close the triangular gap. It also strengthens overall gum health. The downside is that it involves surgery and requires healing time.

Bioclear Matrix Technique

A newer, innovative solution is the Bioclear Matrix Technique. This method uses clear matrices and composite resin to rebuild the teeth without heavy drilling or enamel removal.

It’s minimally invasive, preserves your natural tooth structure, and provides excellent cosmetic results. However, it’s only available through dentists trained in this specific technique.

Treatment for Black Triangles: What’s Right for You?

The best treatment for black triangles depends on what caused them in the first place:

• Mild Cases: Bonding or Bioclear composite is often ideal.
• Severe Gum Recession: Soft tissue grafting may be required.
• Misalignment-Related Gaps: Orthodontics or clear aligners.
• Cosmetic Enhancement: Veneers for long-lasting aesthetics.

A dentist will evaluate your gums, bone levels, and tooth shape before recommending the most effective option.

Preventing Black Triangles Teeth

While some causes, like natural tooth shape, can’t be avoided, you can lower the risk of developing gum recession gaps by following these habits:

• Brush gently with a soft-bristled toothbrush to protect your gums from unnecessary wear and irritation.
• Floss daily with care, sliding the floss instead of snapping it into the gums to avoid trauma.
• Avoid tobacco use, as it contributes to gum disease and tissue loss.
• Schedule regular dental cleanings and check-ups to keep your gums healthy and detect early problems.
• Wear retainers after orthodontic treatment to maintain tooth alignment and prevent new gaps from forming.

Treating Black Triangles Teeth with ALIGNERCO

If your black triangles are caused by tooth misalignment, ALIGNERCO Clear Aligners offer an affordable and discreet way to bring your teeth into better alignment and reduce unwanted gaps. These at-home clear aligners gradually shift your teeth, helping close spaces while improving overall smile balance, without the need for metal braces.

Final Thoughts on Black Triangles Teeth

Black triangle teeth might look like a small cosmetic problem, but they can impact both your confidence and your oral health. These gaps can appear due to gum recession, bone loss, or simply the natural shape of your teeth.

Fortunately, modern dentistry offers several ways to treat gum gaps, from quick fixes like bonding and veneers to advanced options such as Bioclear treatments.

If you notice these small triangular spaces in your smile, consult a dentist to explore the best treatment for black triangles tailored to your needs. With the right care, you can restore not just your smile’s beauty, but also its long-term health.