How to Fix Black Triangles Between Teeth After Braces

You finished your braces, your teeth are straighter — but now you've noticed dark, triangular gaps near the gumline between certain teeth. These spaces, commonly called black triangles (or gingival embrasures in clinical terms), are one of the most frequently asked-about cosmetic concerns after orthodontic treatment. This guide explains why they happen, what can realistically be done about them, and how a short course of clear aligners — sometimes combined with other techniques — may help reduce or close these spaces.

Who This Guide Is For

This article is written for UK patients who:

• Have completed orthodontic treatment (braces or aligners) and noticed black triangles between teeth that weren't there before — or have become more obvious since treatment
• Are self-conscious about dark gaps near the gumline when smiling or talking
• Want to understand whether a short course of invisible braces could help improve these spaces
• Are researching their options before booking a consultation
• Want honest, balanced information about what can and can't be achieved

If you have bleeding, swollen, or receding gums, or suspect you may have gum disease, see your dentist or periodontist first. Black triangles associated with active gum disease need the underlying condition addressed before any cosmetic or orthodontic treatment is considered.

Key Definitions in Plain English

• Black triangles (gingival embrasures): Dark, triangular gaps visible between teeth near the gumline, where the gum tissue (papilla) doesn't completely fill the space between adjacent teeth.
• Papilla (plural: papillae): The small, pointed triangle of gum tissue that sits between two teeth. When papillae are healthy and full, they fill the space between teeth completely. When they shrink or are lost, black triangles appear.
• Interdental bone: The thin ridge of bone between two adjacent tooth roots. The papilla's shape and height depend on the bone underneath — if bone is lost, the papilla typically recedes too.
• IPR (Interproximal Reduction): A technique where tiny amounts of enamel (typically 0.1–0.5mm) are removed from between teeth to reshape contact points or create small amounts of space. Often used alongside aligners to help close black triangles.
• Composite bonding: Tooth-coloured resin material applied to teeth to reshape them. Can be used to widen the sides of teeth so they fill more of the embrasure space.
• Contact point: The spot where two adjacent teeth touch. Its position relative to the bone crest determines whether a black triangle is visible.
• Tracking: How well teeth are following the planned movement sequence during aligner treatment. Good tracking means the aligners fit snugly and movements are progressing as planned.
• Refinements: Additional sets of aligner trays produced after the initial series to fine-tune the result.
• Retainers: Custom-made devices worn after treatment to hold teeth in their new positions.
• 3D scan: A digital impression of your teeth used for diagnosis and treatment planning.

What Causes Black Triangles Between Teeth?

Black triangles are not a single problem with a single cause. They result from a combination of factors, which is why they can be challenging to fix completely.

1. Tooth Shape

Teeth come in different shapes. Some people have teeth that are more triangular or tapered — wider at the biting edge and narrower near the gum. Others have teeth that are more rectangular or square. Triangular-shaped teeth naturally have larger embrasure spaces near the gumline because their contact point (where adjacent teeth touch) sits higher up, leaving more space below for the papilla to fill.

If the papilla can't fill all of that space, a black triangle becomes visible. This is a structural, anatomical factor — it's about tooth geometry, not disease.

2. Bone Loss and Gum Recession

The gum papilla is supported by the interdental bone underneath. If bone has been lost — due to periodontal (gum) disease, aggressive brushing, trauma, or natural ageing — the papilla loses its scaffold and shrinks. Once interdental bone is lost, it typically doesn't regenerate on its own, which is why black triangles caused by bone loss are the most difficult to reverse.

3. Orthodontic Treatment Itself

This is the factor most relevant to patients reading this guide. Orthodontic treatment (braces or aligners) can unmask or create black triangles in several ways:

• Unmasking pre-existing spaces: If teeth were severely crowded or overlapping before treatment, the crowding may have been hiding embrasure spaces. When teeth are aligned, the true shape of the papillae becomes visible.
• Changes in root angulation: Moving teeth changes the angle between roots. If roots are tipped closer together, the contact point moves toward the gum, potentially closing a triangle. If roots diverge, the triangle may open.
• Gum inflammation resolution: Crowded teeth are harder to clean, so gums around crowded teeth are often slightly swollen (inflamed). Once teeth are aligned and cleaning improves, the inflammation resolves and the gum tissue shrinks to its true, healthy volume — which may be smaller than when it was swollen.
• Tissue remodelling: Gum and bone tissue remodel during orthodontic movement. In some cases, this can result in slight papilla reduction.

4. Age and Biology

Gum papillae tend to shrink gradually with age, even without disease. Some research suggests that after age 40, papilla height decreases naturally. Genetics also play a role — some people are more prone to thin, delicate gum tissue ("thin biotype") that's less likely to fill embrasure spaces fully.

5. Oral Hygiene Habits

Aggressive brushing with a hard-bristled brush, incorrect flossing technique, or overuse of interdental brushes that are too large can damage the papillae over time. Conversely, poor oral hygiene leading to gum disease causes bone and tissue loss.

What Clear Aligners Can Do (and What They Can't)

Clear aligners can be a useful tool for addressing black triangles — but they're not a standalone magic fix. Understanding what they can and can't do is important for setting realistic expectations.

What Aligners Can Do

• Reposition teeth to lower contact points: By tipping or bodily moving adjacent teeth slightly, the contact point between them can be moved closer to the gumline. This reduces the visible triangle above the papilla. This is one of the most effective strategies for black triangle reduction.
• Close residual spacing: If black triangles are partly due to small gaps between teeth (rather than just gum recession), aligners can close these spaces.
• Optimise root angulation: Adjusting root positions so that adjacent roots are more parallel (rather than diverging) can reduce embrasure size.
• Work with IPR: Aligners and IPR are often used together. IPR reshapes the contact area, and the aligner then closes the modified space — effectively moving the contact point to a more favourable position.

What Aligners Can't Do

• Regrow bone or gum tissue: Aligners move teeth — they don't regenerate lost bone or papillae. If the black triangle is caused by significant bone loss, alignment alone won't fill the space.
• Change tooth shape: Aligners reposition teeth but don't alter their anatomy. If teeth are very triangular, alignment alone may not close the triangle — it may need to be combined with bonding or IPR.
• Guarantee papilla regrowth: Even when teeth are repositioned ideally, the papilla may or may not grow back to fill the space. Younger patients with healthy gums tend to respond better, but outcomes vary.
• Fix large triangles in isolation: Severe black triangles usually need a multi-disciplinary approach (alignment + bonding + periodontal management), not just aligners.

Step by Step: How Treatment Typically Works

Fix Options: What's Available and How They Compare

There's no single "best" fix for black triangles — the right approach depends on the cause, severity, and your individual anatomy. Here's how the main options compare.

1. Clear Aligner Treatment (Repositioning)

A short course of clear aligners can reposition teeth to move contact points closer to the gumline, reducing the visible triangle. This is often the most effective single intervention for post-orthodontic black triangles where tooth position is a contributing factor.

• Best for: Black triangles where tooth position or root angulation is contributing to the gap
• Often combined with: IPR (see below)
• Treatment time: Typically 3–12 months for focused black triangle cases
• Limitations: Can't regrow gum tissue; may not fully close large triangles

2. IPR (Interproximal Reduction)

IPR involves removing very small amounts of enamel from the sides of teeth (typically 0.1–0.5mm per surface) to reshape the contact area. When combined with aligner treatment, IPR allows the contact point to be moved closer to the gumline as teeth are brought together.

• Best for: Teeth with high, narrow contact points; triangular-shaped teeth
• How it helps: Creates a broader contact area lower on the tooth, reducing the height of the triangle
• Safety: Within recommended limits, IPR is considered safe and doesn't increase cavity risk
• Limitations: There's a maximum amount of enamel that can safely be removed; won't help if bone loss is the primary cause

3. Composite Bonding

Tooth-coloured composite resin is applied to the sides of teeth to make them wider, effectively filling in the dark space. This is a cosmetic camouflage rather than a structural fix.

• Best for: Small to moderate triangles; cases where alignment is already good but tooth shape creates gaps
• Advantages: Immediate visible improvement; no tooth movement required; reversible
• Limitations: Can look bulky if overdone; may chip or stain over time; needs maintenance or replacement; harder to clean around
• Often combined with: Alignment and IPR for a more natural result

4. Porcelain Veneers

Custom-made porcelain shells bonded to the front of teeth can change both the shape and width of teeth, closing black triangles more permanently than composite bonding.

• Best for: Cases where multiple cosmetic improvements are wanted alongside black triangle closure
• Advantages: Durable; stain-resistant; can transform the overall appearance
• Limitations: Irreversible (tooth preparation required); more expensive; not suitable for all teeth

5. Gum Health Optimisation

Improving gum health through professional cleaning, better home care, and treating any underlying gum disease can, in some cases, allow partial papilla regrowth — particularly if the black triangles are relatively new and the bone support is intact.

• Best for: Early-stage triangles where gum inflammation was masking the true tissue level
• Practical steps: Professional hygiene appointments; gentle brushing technique; correctly sized interdental brushes; regular dental check-ups
• Limitations: Limited tissue regeneration once bone is lost; results are unpredictable

6. Surgical Options (Specialist)

In some cases, periodontal procedures such as gum grafting or papilla reconstruction may be considered. These are specialist procedures typically reserved for severe cases.

• Best for: Significant gum recession or bone loss; cases that haven't responded to other approaches
• Limitations: Variable success rates for papilla reconstruction; more invasive; requires specialist referral

Suitability Checklist

Not every black triangle case is suitable for aligner treatment. This checklist can help you understand where you might fit — but only a clinical assessment can confirm suitability.

When to Seek Advice

Black triangles are primarily a cosmetic concern in most cases, but certain signs warrant a clinical assessment sooner rather than later:

• Bleeding gums: If your gums bleed when brushing or flossing, this may indicate gum disease that needs treatment before any cosmetic work
• Progressive gaps: If the triangles seem to be getting larger over time, this could suggest ongoing bone or tissue loss that needs investigation
• Pain or sensitivity: Black triangles themselves don't cause pain — if you have pain or sensitivity, see your dentist to rule out other issues
• Food trapping: If food is constantly getting stuck in the gaps, this can contribute to further gum irritation and decay risk — worth addressing for hygiene reasons as well as cosmetic ones
• Loose teeth: If any teeth feel mobile, see your dentist promptly — this is not related to black triangles per se but indicates a more serious issue

Risks, Side Effects, and Limitations

Any treatment for black triangles carries considerations that should be discussed with your clinician.

Aligner Treatment

• Temporary pressure and mild discomfort when starting new trays (typically settles in 1–3 days)
• Minor speech changes with new trays (resolves quickly)
• Requires discipline with wear time — approximately 22 hours per day for optimal tracking
• Results are not guaranteed — some black triangles may improve significantly, others only partially
• Treatment may take longer than initially planned if refinements are needed

IPR

• Irreversible — enamel doesn't regrow
• Within recommended limits (typically no more than 0.5mm per surface), it's considered safe
• Mild temporary sensitivity is possible
• Excess IPR could theoretically weaken a tooth, but this is extremely unlikely when performed correctly

Composite Bonding

• May chip, stain, or wear over time — typically needs replacement every 5–10 years
• Creates areas that are harder to clean — meticulous oral hygiene is important
• If overdone, can look bulky or unnatural
• Not as durable or stain-resistant as porcelain

General Limitations

• Complete elimination of black triangles is not always possible, particularly when bone loss is involved
• Papilla regrowth after tooth repositioning is variable and cannot be guaranteed
• Results may change over time as gums age naturally
• Multiple treatment modalities may be needed, increasing complexity and cost

How Long Treatment May Take

Treatment duration depends on the approach used and the severity of the black triangles.

What Affects Treatment Time?

• Number and location of black triangles: More triangles or triangles on back teeth may take longer
• Severity: Larger triangles typically require more tooth movement and possibly more treatment modalities
• Gum health: If periodontal treatment is needed first, this adds time
• Compliance: Consistent aligner wear (approximately 22 hours/day) is essential for on-time tracking
• Refinements: Most cases benefit from at least one round of refinement trays
• Biology: Individual response to tooth movement and papilla regrowth varies

Costs in the UK

Treatment costs vary depending on the approach, complexity, and provider. Attachments, IPR, and refinements are typically included in aligner treatment fees, but confirm this with your provider.

For a more detailed breakdown of aligner pricing, see our guide on invisible braces costs in London.

How to Keep Results: Retention and Aftercare

Closing or reducing black triangles is only half the challenge — keeping them closed is equally important.

Retention

• Fixed retainers: A thin bonded wire behind the front teeth provides continuous passive retention, helping maintain tooth positions and contact points
• Removable retainers: Clear plastic trays worn nightly to maintain all tooth positions
• Combination: Many clinicians recommend both for maximum stability — particularly important for black triangle cases where even small tooth movements could reopen gaps

Gum Health Maintenance

• Use a soft-bristled toothbrush — medium or hard bristles can damage papillae over time
• Brush gently with small circular motions; avoid aggressive scrubbing
• Use correctly sized interdental brushes — too large and they can damage tissue; too small and they won't clean effectively. Your hygienist can recommend the right size
• Consider using a water flosser as a gentle supplement to interdental brushing
• Attend regular hygiene appointments (every 3–6 months, as recommended)
• Address any gum bleeding or recession promptly with your dentist

Protecting Bonding

If composite bonding was used to camouflage remaining black triangles:

• Avoid biting directly into very hard foods
• Minimise staining foods and drinks (coffee, red wine, turmeric) or rinse afterwards
• Don't use whitening toothpaste with large abrasive particles directly over bonding
• Attend regular dental check-ups — your dentist can monitor bonding integrity and polish or repair as needed

Frequently Asked Questions

What exactly are black triangles between teeth?

Black triangles — clinically called gingival embrasures — are dark, triangular gaps visible between teeth near the gumline. They appear when the gum tissue (papilla) between two adjacent teeth doesn't completely fill the space. The "black" refers to the dark shadow of the mouth visible through the gap, not a stain or discolouration on the tooth.

Are black triangles after braces normal?

They're common, particularly after treatment that resolved significant crowding or overlapping. The crowded teeth may have been hiding these spaces, and once straightened, the true embrasure shape becomes visible. It doesn't necessarily mean anything went wrong with the orthodontic treatment — in many cases, the triangles were always there structurally, just hidden by the overlap.

Can black triangles go away on their own?

In some cases, gum papillae may partially regrow after orthodontic treatment — particularly in younger patients with good bone support and excellent oral hygiene. This process can take 6–12 months after treatment. However, significant black triangles caused by bone loss or tooth shape are unlikely to resolve without intervention.

Can clear aligners fix black triangles?

Clear aligners can help reduce black triangles by repositioning teeth so that contact points sit closer to the gumline. This is often combined with IPR to reshape the contact area. Aligners are generally most effective when tooth position is a contributing factor. They cannot regrow lost bone or gum tissue, so complete elimination isn't always achievable.

Does IPR hurt?

Most patients describe IPR as painless or mildly uncomfortable. It involves removing very thin layers of enamel (fractions of a millimetre) from between teeth using gentle filing strips or a fine rotary instrument. No anaesthetic is typically needed. Some patients experience brief sensitivity afterwards, which usually resolves within a day or two.

Will composite bonding look natural?

When performed by a skilled clinician, composite bonding can look very natural. The composite is shade-matched to your tooth colour and sculpted to mimic natural tooth contours. However, the quality of the result depends on the clinician's skill, the size of the area being filled, and the location. Very large fills are harder to make look completely natural. Composite may also stain or discolour over time, requiring maintenance.

How do I prevent black triangles from getting worse?

The most important prevention strategies are maintaining excellent gum health (gentle brushing, correct interdental cleaning, regular hygienist visits), wearing retainers as prescribed, and addressing any gum disease early. Avoid aggressive brushing and oversized interdental brushes, which can damage papillae. If you smoke, stopping can improve gum health significantly.

Are black triangles a sign of gum disease?

Not necessarily. While gum disease (periodontitis) can cause bone loss that leads to black triangles, the most common causes are tooth shape and post-orthodontic unmasking. However, if black triangles are accompanied by bleeding gums, gum recession, loose teeth, or persistent bad breath, a gum health assessment is advisable to rule out periodontal disease.

Can I get black triangles fixed on the NHS?

Generally, no. The NHS categorises black triangle treatment as cosmetic rather than functional (unless there's an underlying clinical need like gum disease requiring treatment). Cosmetic dental work is typically only available privately in the UK. Your NHS dentist can treat any underlying gum disease, but the cosmetic closure of black triangles would usually need to be arranged privately.

How long does a short aligner course take for black triangles?

Focused aligner treatment specifically for black triangle reduction typically takes 3–12 months, depending on the number and severity of triangles, whether IPR is needed, and whether refinement trays are required. Mild cases with 1–2 small triangles may be resolved in as few as 3–6 months. More complex cases involving multiple teeth or combined approaches may take longer.

Will my black triangles come back after treatment?

If treatment successfully closes or reduces black triangles and you maintain good retention (wearing retainers as prescribed) and gum health, the results can be long-lasting. However, natural ageing, gum recession, and changes in gum health could potentially lead to some recurrence over time. Consistent aftercare is key to maintaining results.

Should I wait to see if my gums fill in after braces before getting treatment?

It's generally reasonable to wait 6–12 months after completing orthodontic treatment to see if gum papillae recover on their own — particularly if you're young and have good bone support. During this time, focus on excellent oral hygiene and regular dental visits. If the triangles haven't improved after a year, they're unlikely to resolve without intervention, and a consultation to discuss options would be appropriate.

Disclaimer: This article is for general information only and does not constitute dental or medical advice. Treatment needs, timelines, and costs vary by individual case. All cost figures are approximate UK ranges for reference and are not quotations. Whether treatment is suitable and which approach is appropriate can only be determined through an in-person clinical assessment by a GDC-registered dental professional.