“Black triangles” are the small dark gaps that can appear between teeth near the gumline, where gum tissue no longer fills the space. They are common, especially in adults, and can affect both appearance and how easily food gets trapped.
What causes black triangles?
- Gum recession — gums can shrink back with age, aggressive brushing or gum disease.
- Bone loss — the gum between teeth is supported by bone; if the bone reduces, the gum follows.
- Tooth shape — triangular-shaped teeth touch only near the biting edge, leaving a larger space near the gum.
- Tooth movement — black triangles sometimes appear after teeth are straightened, as crowded, overlapping teeth are aligned.
- Previous dental work — the shape of older fillings or crowns can affect the space.
Are black triangles a problem?
Often they are mainly a cosmetic concern. But they can also:
- trap food and plaque, increasing the risk of decay and gum inflammation
- be a sign of underlying gum disease that needs treatment first
- affect speech slightly in some people
That’s why the first step is always a check-up to assess your gum health.
Treatment options
Your dentist will explain which options suit your situation, along with their benefits, risks and costs.
Treat gum health first — if gum disease is present, periodontal treatment comes before any cosmetic work.
Composite bonding — tooth-coloured resin is added to the sides of the teeth to close or reduce the gap. This is often done without removing tooth structure. Some techniques use clear matrix systems to shape the resin close to the gum. See composite bonding.
Clear aligners — where tooth position or shape contributes, aligner treatment combined with minor reshaping between teeth can sometimes reduce the gap. See Invisalign and clear aligners.
Veneers or crowns — can change tooth shape to reduce the space, usually considered where other work is also planned. See veneers.
Gum procedures — in some cases a referral to a periodontist may be discussed.
Looking after the area
- Use interdental brushes sized by your dentist or hygienist.
- Brush gently with a soft brush — see electric vs manual toothbrush.
- Keep up regular professional cleans.
FAQs
Can black triangles go away on their own?
Gum tissue generally does not grow back on its own once lost, but treatment can often reduce the appearance of the gap.
Is composite bonding for black triangles permanent?
Bonding is long-lasting but not permanent. It can chip or stain over time and may need maintenance.
Do clear aligners cause black triangles?
Straightening crowded teeth can reveal spaces that were hidden by overlapping teeth. Your dentist will discuss this before treatment starts.
Call (02) 4733 1197 or book online for an assessment.
This information is general in nature and is not a substitute for personalised dental advice. Suitability and outcomes vary between individuals, and any procedure carries risks that should be discussed with your dentist. Our dentists are registered with AHPRA.