Black triangles are the small dark gaps that can appear near the gumline between the teeth, where the gum no longer fully fills the space. Dentists call them open gingival embrasures. They are common, especially with age, and while they are mostly a cosmetic concern, they can also trap food and make cleaning harder. The good news is there are several ways to reduce or close them, ranging from simple to more involved.
Key takeaways
- Black triangles are gaps near the gumline where gum tissue has receded or thinned.
- The most common causes are gum recession, gum disease, tooth shape, and ageing.
- They are usually a cosmetic issue but can trap food and plaque.
- Options range from composite bonding and veneers to orthodontics and gum treatment.
- Lost gum tissue rarely grows back, so prevention and early gum care matter.
What causes black triangles
Healthy gum normally sits as a small peak, called the papilla, in the space between two teeth. A black triangle appears when that peak shrinks or the space widens. Several things can cause this.
Gum recession and gum disease
The most common cause is the gum pulling back, whether from age, overly hard brushing, or gum disease that has damaged the supporting tissue and bone. Once the papilla loses its support, it flattens and a gap opens. Our guides to receding gums and gum disease explain how this develops.
Tooth shape and position
Teeth that are more triangular than rectangular meet only near the biting edge, leaving a wider space near the gum. Crowded or tilted teeth can do the same. This is partly why black triangles sometimes appear after orthodontic treatment, as the teeth move into a straighter line.
Ageing and bone loss
The gum peak naturally thins over the years, and any loss of the underlying bone makes a gap more likely. This is why black triangles become more common with age.
How black triangles can be closed
The right option depends on the size of the gap and what is causing it. The table below sets out the common approaches and the general market cost ranges, which are not a quote.
| Option | How it works | Typical market range (AUD) |
|---|---|---|
| Composite bonding | Tooth coloured resin added to reshape the teeth and fill the gap | $150 to $450 per tooth |
| Porcelain veneers | Custom shells that reshape the teeth and close the space | $1,200 to $2,500 per tooth |
| Orthodontics | Aligners or braces to move teeth closer where appropriate | $2,000 to $9,000 for a course |
| Gum and hygiene treatment | Treats the underlying gum disease to prevent worsening | Varies with the case |
Composite bonding is often the simplest and most affordable way to close a small to moderate black triangle, because the resin can be shaped to gently fill the space without removing tooth structure. For larger gaps or a wider smile makeover, veneers may suit better. Our guides to bonding versus veneers and closing a gap between the front teeth compare these in more detail. For a written quote, see our bonding service page or our current deals page.
Can the gum grow back?
Lost gum tissue, especially the small papilla between teeth, rarely grows back on its own. This is why prevention matters. Gentle brushing with a soft brush, daily cleaning between the teeth, and treating gum disease early all help protect the gum peaks you still have. In some cases a dentist or specialist can rebuild lost tissue with grafting, which our guide to gum graft surgery explains, though results between teeth are less predictable than along the gumline.
Frequently asked questions
Are black triangles a health problem?
They are mainly cosmetic, but they can trap food and plaque, which makes good cleaning between the teeth important.
Can I prevent black triangles?
You can reduce the risk by brushing gently, cleaning between your teeth daily, and treating gum disease early before tissue is lost.
Is bonding permanent?
Bonding is durable but not permanent. It may need touch ups or replacement over the years, as our bonding guide explains.
Will whitening hide a black triangle?
No. Whitening changes tooth colour but does not fill the gap. Closing the space needs bonding, veneers or orthodontics.
Do black triangles always need treatment?
No. If they do not bother you and cleaning is manageable, they can simply be monitored. Treatment is a personal choice.
The takeaway
Black triangles form when the gum between the teeth recedes or thins, most often from gum recession, tooth shape or ageing. They are usually cosmetic, and options to close them range from simple composite bonding to veneers or orthodontics, alongside good gum care to stop them worsening. To discuss which option suits you, contact the team at Lumi Dental or see our current deals page.
