The aesthetic judgement of a smile is often left in the eyes of the beholder, and whilst dental professionals and patients may offer different opinions on what can be considered ‘beautiful’, there are common preferences. Between malocclusion and chipped teeth, individuals may agree that black triangles and diastemas are a notable unaesthetic attribute.
Black triangles are caused by both the erosion of tooth enamel from interproximal spaces over time, and the resorption of supportive alveolar bone and gingival tissue.[i] Some patients may also have diastemas throughout the dentition, with maxillary midline diastema being a frequently seen feature of malocclusion, and aetiological factors can include genetic inheritance, a hypertrophic labial frenum, anterior traumatic bite, oral habits such as thumb sucking, and peg-shaped lateral incisors.[ii]
Patients of all ages may seek support for the treatment of these aesthetic and functional issues. Dental professionals should be aware of the potential complications that may arise if the dentition is left untreated, as well as suitable routes for care.
Impact and response
Why are black triangles and diastemas particularly troublesome to patients? On one hand, the aesthetic issue can have significant repercussions in everyday life. Aesthetic dental care is increasingly popular, with the presence of social media in modern life playing no small part.[iii] The literature varies in its reports surrounding judgement of black triangles; some researchers find that women can be more critical in their evaluation of the feature, but this is in contrast to other studies investigating alternative aesthetic factors – the results may vary due to different methods of evaluation, sample demographics, and the different participants.[iv] Self-perception of dental aesthetics are known to impact psychosocial well-being, with consequences for self-esteem and quality of life.[v]
Patients may also face functional challenges as a result of developing open gingival embrasures, or having diastemas. The interdental spaces can cause food impaction, improper plaque control, and cause phonetic problems – these once again may impact self-esteem, but also the first two issues will compromise oral health.[vi]
It’s important to note that black triangles or diastemas may also be a result of orthodontic treatment, and clinicians may have to confront these issues in order to deliver an optimal final result. If this is the case, patients should be aware that post-orthodontic restorations are likely to be required, for full informed consent.
Dental professionals should first advise patients with spaces in the dentition on how to manage their oral hygiene routines for the best possible outcomes. This would include regular toothbrushing, alongside interdental cleaning, which will debride plaque and bacteria from this at-risk areas.
Subsequent care will aim to optimise aesthetics and function by eliminating open embrasures and diastemas. To do so, clinicians should be aware of the effective restorative solutions available, and develop skills to apply them with confidence.
Appropriate interventions
Whether managing cases where black triangles and diastemas have appeared naturally, or as a result of orthodontic treatment, professionals should be able create a uniform dentition with predictable and efficient approaches.
Injection moulding techniques have been recognised as an approach that is repeatable and predictable, with a flowable or heated (thermoviscous) composite applied to cover the tooth, creating an aesthetic and functional result.[vii] This approach can be preferred by the patient, as the technique requires minimal tooth preparation, limiting chair time for a more efficient workflow.vii
Perhaps most importantly, it’s an additive approach to care. Whilst an alternative such as a veneer or crown may be suggested by some professionals, one must be aware of the need for the removal of natural tissue to accommodate for the restoration; where the tooth is healthy, and an aesthetic outcome is all that is desired, injection moulding stands as an ideal, minimally invasive solution.
The use of full composite veneers, and similar treatment applications, may still be indicated in some cases, where tooth morphology and local anatomy suits such a protocol. However, to judge when this is necessary, a professional should be appropriately trained, and be able to confidently identify suitable cases.
Trust your training
When looking to develop restorative skills, especially in the management of black triangles and diastemas, clinicians should seek out courses by widely-recognised and trusted providers.
IAS Academy presents the new Restorative Space Closure course, with two dates confirmed and available for professionals in 2026. The course is led by Dr Nik Sethi, Director at Elevate and current President of the British Academy of Aesthetic Dentistry (BAAD), and Dr Sanjay Sethi, Past President of the BAAD and Director of the Aesthetix and Elevate education programmes. It equips professionals with the skills to assess pre-orthodontic risks for black triangles, use injection moulding methods with confidence, manage mini diastemas mid- or post-orthodontic treatment, and more.
As both an aesthetic and functional concern, black triangles and diastemas need to be treated with support from the dental team. Seeking educational opportunities to develop skills ensures clinicians can restore smiles with confidence.
For more information on upcoming IAS Academy training courses, please visit www.iasortho.com or call 01932 336470 (Press 1)
Author: Dr. Tif Qureshi
[i] Kaur, A., Waghmare, P., Dodwad, V. M., Bhosale, N. S., Karale, A. M., & Singh, S. S. (2023). Black Triangle and its Management in Dentistry: A Review Article. Indian Journal of Dental Sciences, 15(2), 99-104.
[ii] Abrahams, R., & Kamath, G. (2014). Midline diastema and its aetiology–a review. Dental update, 41(5), 457-464.
[iii] Abbasi, M. S., Lal, A., Das, G., Salman, F., Akram, A., Ahmed, A. R., … & Ahmed, N. (2022, October). Impact of social media on aesthetic dentistry: General practitioners’ perspectives. In Healthcare (Vol. 10, No. 10, p. 2055). MDPI.
[iv] Al-Omiri, M. K., Atieh, D. W. A., Abu-Awwad, M., Al Nazeh, A. A., Almoammar, S., Hassan, S. A. B., … & Lynch, E. (2024). The knowledge regarding the impacts and management of black triangles among dental professionals and laypeople. Scientific Reports, 14(1), 10840.
[v] Militi, A., Sicari, F., Portelli, M., Merlo, E. M., Terranova, A., Frisone, F., … & Settineri, S. (2021). Psychological and social effects of oral health and dental aesthetic in adolescence and early adulthood: an observational study. International Journal of Environmental Research and Public Health, 18(17), 9022.
[vi] Nursolihati, V., & Louisa, M. (2025). Black triangle: Etiology and treatment management. In Current Research and Trends in Dental and Medical Technology (pp. 241-248). CRC Press.
[vii] Veneziani, M. (2025). Composite Injection Molding Technique: Innovative Customized Hybrid Index and updated clinical procedures: Part 1. International Journal of Esthetic Dentistry, 20(1).
