If you’ve noticed new gaps between your teeth, or small dark spaces near the gumline that weren’t there before, you’re not alone. These are often called “black triangles,” and they usually happen when the gum tissue between teeth reduces or when tooth shape and alignment change.

The important thing is to separate two different issues. One is the look of the gap. The other is what it might be telling you about your gum health. Some black triangles are mainly cosmetic. Others are an early sign of gum disease or recession that needs attention.

Key takeaways

• Gum recession and black triangles are common and often
• The priority is identifying whether gum disease is present and stabilising
• Brushing technique, tooth shape, and orthodontic changes can all play a
• Treatment ranges from prevention and gum therapy through to cosmetic options in selected cases.

What are “black triangles”?

A black triangle is the dark space you see between teeth near the gumline. It happens when the gum “papilla” (the little triangle of gum tissue between teeth) is reduced or no longer fills the space.

Sometimes the triangle was always there but became more visible as gums receded slightly. Sometimes it appears after orthodontic alignment because teeth straighten and contacts shift, revealing the underlying tooth shape.

Why gums recede

Gum recession means the gum margin moves down (or up, depending on the tooth), exposing more of the tooth root. Roots are more sensitive than enamel and are more prone to wear.

Common causes include:

• Gum disease (periodontal disease): inflammation and bone loss can reduce gum support and create spaces.
• Overbrushing or aggressive technique: scrubbing horizontally at the gumline can push gums back over time, especially with a hard brush.
• Thin gum anatomy: some people naturally have thinner gum tissue that’s more prone to recession.
• Grinding and bite overload: excessive forces can contribute to gum trauma and recession patterns.
• Crowding and tooth position: teeth positioned outside the bone envelope can be more prone to recession.
• Smoking and vaping: increases gum disease risk and can worsen long-term

Why gaps and black triangles happen

Black triangles are often a combination of gum tissue and tooth shape. Many teeth are naturally more triangular, meaning they touch near the top but taper inward toward the gumline. If gum tissue reduces even slightly, a space becomes visible.

Other reasons include:

• Bone loss from gum disease, which reduces the support for gum tissue between
• Orthodontic alignment, which can shift teeth into a straighter position and change contact points.
• Food traps and inflammation, where persistent irritation makes gums shrink
• Age and natural tissue changes, which can make gum contours change over

The first question we need to answer: is it gum disease?

Before discussing cosmetic fixes, the priority is checking gum health. If gum disease is active, closing gaps without stabilising the underlying problem is a short-term solution.

A gum assessment typically includes:

• gum measurements around teeth
• checking for bleeding and inflammation
• checking tartar build-up and plaque traps
• sometimes imaging if indicated to assess bone levels If gum disease is present, stabilisation usually comes first.

Prevention: what helps slow recession and reduce progression

Most people don’t need a complicated plan. They need a correct technique and consistency. Helpful habits include:

• use a soft brush and gentle pressure, especially along the gumline
• avoid aggressive scrubbing (more force is not better)
• clean between teeth daily (floss or interdental brushes) to reduce inflammation
• manage grinding if it’s contributing (night guard may be relevant in some cases)
• reduce smoking/vaping where possible

If you’re not sure about technique, ask. Small changes can make a big difference over time.

Treatment options: what can be done?

Treatment depends on what’s causing the issue and what outcome you want.

If the issue is mainly gum inflammation or early gum disease

Professional cleaning and gum therapy can reduce swelling and bleeding, and help stabilise the tissues. Once inflammation is controlled, gums often look healthier, though recession that has already occurred may not fully reverse.

If the issue is tooth shape and “open embrasures”

In selected cases, small cosmetic bonding can reduce the appearance of black triangles. This has to be planned carefully because over-bulking teeth can make cleaning harder and increase gum inflammation.

If the issue is orthodontic alignment

Sometimes aligners can improve contacts and reduce gaps, but they can also reveal triangles depending on tooth shape. That’s why planning and expectations matter.

If recession is significant

In some cases, gum grafting or specialist periodontal care may be discussed. This is very individual and depends on anatomy, severity, and goals.