Avoiding the black triangle in midline diastema | Dr Subir Banerji


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Post: Avoiding the black triangle in midline diastema

Avoiding the black triangle in midline diastema 10 years 2 weeks ago

Black triangles or open gingival embrasures form between teeth when there is loss of interdental papilla and it roughly affects 38% of the population(1). These black triangles are considered unaesthetic and can have a negative impact on the attractiveness of a smile. It could contribute to collection of food debris and also result in awkward escaping of saliva during speech and mastication. One of the major challenges for any practicing dentist would be to avoid formation of a black triangle during the closure of a diastema with direct composite resin.

It has been established in studies that there is a direct correlation between effect of distance between the crest of alveolar bone to the contact point between teeth on the presence of absence of interdental papilla(2)

The contact point is the point on the proximal surface of two adjacent teeth where they touch each other. The best way to get to know about a contact point is through passing floss between teeth. Contact point is that location where one feels resistance while the floss is passed through(3).

Interdental papilla is that part of the gingival tissue found in space between the teeth(4). The interdental papilla (gingiva) is unique as it has limited regeneration potential and it shows distinct cellular and molecular properties from other parts of gingiva(5).

In the video below a clinical case is shown which involves the closure of a midline diastema with direct composite resin to avoid the presence of a black triangle and establishing the ideal positioning of the contact area between the teeth.

It is possible to achieve pleasant interdental papilla contour after closure of a diastema by utilizing direct composite resin. Ideally, if possible the contact area should start gingivally about 5-6mm superior to the crest of the interdental alveolar ridge.


1. Kurth JR, Kokich VG. Open gingival embrasures after orthodontic treatment in adults: prevalence and etiology. Am J Orthod Dentofacial Orthop 2001 Aug;120(2):116-23.
2. Tarnow DP, Magner AW, Fletcher P. The Effect of the Distance From the Contact Point to the Crest of Bone on the Presence or Absence of the Interproximal Dental Papilla. Journal of Periodontology. 1992 2013/08/26;63(12):995-6.
3. Publishing I. [cited]; Available from: medical.tpub.com/14274/css/14274_67.htm.
4. Care AcD. [cited]; Available from: dentistry.about.com/od/termsanddefinitions/g/interdentalp.htm.
5. Csiszar A, Wiebe C, Larjava H, Hakkinen L. Distinctive molecular composition of human gingival interdental papilla. J Periodontol 2007 Feb;78(2):304-14.
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