What to Do About Black Triangles Between Your Teeth

As ultra-bright, celebrity-style smiles grow more sought-after, an increasing number of people look to correct imperfections in their teeth.

One common concern is the presence of black triangles—also known as open gingival embrasures—between teeth.

Repairing these spaces isn’t purely cosmetic. There are meaningful health reasons to address these gaps as well.

What are open gingival embrasures or black triangles?

Put simply, they’re triangular voids that form between adjacent teeth. Approximately 67 percent of adults over 20 have them.

It’s useful to know how they arise and what options exist for managing them, since they can contribute to additional oral health issues.

What causes them?

If you’re spotting gaps appearing between your teeth, bring it up with your dentist.

Black triangles can develop for a variety of reasons, many of which relate to the condition of your gums and supporting bone.

Gum recession

Healthy, full gums snugly occupy the spaces between teeth.

Gums can recede because of age, tobacco use, or periodontal (gum) disease. When gums pull away, roots may become exposed and more susceptible to plaque, bacteria, and decay.

Bone loss

Conditions like gum disease or osteoporosis can lead to bone loss around a tooth’s root. When bone diminishes, the overlying gum often follows, creating black triangles.

Dental hygiene habits

Gum tissue is delicate. Overzealous brushing can harm gums over time.

A 2011 study noted that interproximal cleaning tools—tiny brush-like devices used between teeth—can also produce black triangles if the head is too large for the space.

Orthodontic treatment

When teeth are moved during orthodontic care, small gaps can open up as they settle into new alignments.

Orthodontic components can also irritate or injure the gums in some cases.

A 2018 study reported that adults with braces had a 22 percent chance of developing black triangles between upper incisors and 36 percent between lower incisors.

Triangular tooth shape

Some teeth are relatively rectangular, with similar widths at the gumline and biting edge.

Others taper toward the gumline, creating a more triangular profile; those teeth are more prone to forming these spaces.

Thin, fragile tissue

The thickness of gum tissue varies among individuals.

A 2013 review found that thin gum biotypes are less robust, so following procedures like crowns, implants, or periodontal surgery the gums may not recover their previous fullness.

How can you eliminate the gaps?

Treatments depend on what’s causing the space and how pronounced it is.

Below are several approaches to discuss with your dentist or periodontist.

Gentle dental hygiene

The American Dental Association (ADA) recommends brushing twice daily and flossing. The ADA stresses flossing carefully to avoid harming gum tissue.

If the black triangles are slight and the gums are otherwise healthy, modifying brushing and flossing techniques may allow gums to rebound.

Hyaluronic acid treatment

In certain cases dentists can encourage gum tissue regeneration by injecting hyaluronic acid.

Some proponents prefer this non-surgical route because it’s less painful and recovery is quicker.

Because it’s a relatively recent approach, long-term durability of results is not yet well-established.

Composite resin

Many patients choose to have their dentist fill gaps using composite resin bonding.

Depending on what’s needed, your dentist may use pink resin, tooth-colored composite, or a combination to fill the black triangles.

This is a non-surgical option and can take months in some cases, as the resin is layered thinly for a natural look and to allow the gums to adapt to the narrowed space.

To improve tooth shape further, a dentist might apply tooth-colored composite veneers to create a fuller appearance.

Braces

If gaps developed after tooth movement, orthodontic treatment can sometimes close those spaces by bringing teeth closer together.

Orthodontics require time and expense, but the cosmetic and functional benefits can justify the investment.

Veneers

Ceramic or porcelain veneers can be bonded to the visible surfaces of teeth to mask gaps and create a more uniform smile.

Applying veneers usually means altering the tooth surface slightly so the veneer bonds securely. Experts report veneers can last between 18 months and 20 years.

Surgical remedies

For significant gum recession, periodontists may suggest soft tissue grafting. A periodontist specializes in gum disease and implants.

In grafting, tissue is commonly taken from the palate and placed over receded gum areas. Bone grafts may also be required to rebuild bone at the tooth base.

When appropriate, a clinician might use a pinhole technique to loosen and reposition gum tissue, securing it with collagen strips.

This method is less invasive because it avoids large incisions and sutures that could disrupt blood flow to the area.

In a small study of five participants, pinhole surgical repair was reported as 96.7 percent successful in correcting black triangles.

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The bottom line

Black triangles, known as open gingival embrasures, form when gum tissue retracts from the tooth surface.

Factors such as aging, aggressive oral care, periodontal disease, bone loss, and the shape and thickness of teeth and gums all play roles in their development.

People seek correction not only for looks but because the spaces trap food and bacteria, increasing the risk of further dental issues.

Treatment options range from changing brushing and flossing habits to professional interventions.

Depending on how severe the condition is, your dental team might recommend hyaluronic acid injections, composite bonding, veneers, orthodontics, or surgery.

If you’re noticing black triangles between teeth, consult your dentist to determine which treatment is most appropriate for your situation.