Black triangles between teeth — why they appear and how they can be improved

Key facts

• Dark gap where the gum papilla no longer fills the space
• Causes: recession, bone loss, tooth shape, orthodontics
• Treat gum disease before cosmetic work
• Bonding reshapes teeth to close the gap
• IPR moves contacts closer to the gum

What black triangles are

Between healthy teeth, a small point of gum called the papilla fills the triangular space beneath where neighbouring teeth touch. When this papilla is shorter than the space, a dark gap appears — the “black triangle”, technically called an open gingival embrasure. Whether the papilla fills the gap depends largely on the distance from the contact point between the teeth to the underlying bone: when that distance increases, the gum is less likely to fill the space completely. Black triangles are most noticeable between the upper and lower front teeth and can make a smile look older even when teeth are healthy.

Common causes

Gum recession and bone loss from past or present gum disease are frequent causes, as the papilla shrinks with the supporting bone. Ageing naturally thins gums. Aggressive brushing can contribute to recession. Teeth with a triangular shape — wide at the edge and narrow at the neck — leave a bigger space near the gum. After orthodontic treatment, teeth that were overlapping are straightened and a previously hidden gap may become visible. Black triangles may also appear after gum surgery, around crowns or implants, or where roots diverge. Identifying the cause matters because active gum disease must be treated before any cosmetic correction.

Composite bonding to close black triangles

Composite bonding is one of the most direct ways to reduce black triangles. Tooth-coloured resin is added to the sides of the teeth near the gum line, changing their shape from triangular to more square so the contact point moves closer to the gum and the space shrinks. It usually needs little or no removal of enamel and can be completed in one visit. Careful shaping is essential so the area remains easy to clean with floss or interdental brushes; overhanging bonding can trap plaque and irritate the gum. Bonding can stain or chip over time and needs regular polishing and occasional repair.

Orthodontic IPR and gum options

When teeth are triangular and the patient is having or considering orthodontic treatment, interproximal reduction (IPR) — removing a very small amount of enamel between teeth — lets them be moved closer together, flattening the contact and lowering it toward the gum. This is planned as part of aligner or brace treatment, which the clinic’s orthodontic team can assess. Gum treatments aim first to stop further loss by treating gum disease and improving cleaning technique. Surgical gum grafting or papilla reconstruction can sometimes help, but results in rebuilding papillae are less predictable. Porcelain veneers or crowns with modified shapes are another option for some patients.

Assessment with Dr. Manhal Helfawee

At Manhal Medical Center in Dubai, Dr. Manhal Helfawee, consultant implantologist with more than 20 years in the UAE (DHA licence 00169366-001), whose work includes veneers, crowns and smile refinements, examines your gums, bone levels and tooth shapes, often with X-rays, to understand why the black triangles have appeared. If gum disease is present, it is treated first. He then explains whether bonding, orthodontic IPR, veneers, gum treatment or a combination is most suitable, and what realistic improvement to expect. You receive a written plan. Consultations are in English and Arabic; call +971 4 328 4560.

Composite bonding shapes tooth-coloured resin directly onto the tooth to repair chips, close small gaps or even out edges. It usually needs little or no drilling and is completed in a single appointment.

Prepared by the Manhal Medical Center editorial team · Updated: 2026-10-18 · Treating specialist: Dr. Manhal Helfawee

This page is general information and does not replace a consultation. Suitability, risks and results vary between patients.