Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 20 0 2023 06 14 1 14 Jowel Makdisi Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran solmaz akbari Dental Implant Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran Farid Zayeri Proteomics Research Center and Department of Biostatistics, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran Hoori AslRoosta Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran Siamak Yaghobee Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2020 08 20 2021 01 11 Objectives: The focused question of this systematic review was “does hyaluronic acid (HA) injection in areas of interdental papillary deficiency reduce black triangles?” Materials and Methods: A systematic literature search was performed to find clinical studies on human patients with a minimum of 6-month follow-up, published in English from 2005 to May 2020. There were two outcome variables: black triangle area (BTA) change after treatment at different measurement time points compared with baseline, and patient reported outcome measures (PROMs), when available. Results: Of eight eligible articles (2 randomized clinical trials (RCTs) and 6 non-randomized, non-placebo controlled clinical studies), seven reported that HA injections had a positive impact on reduction of BTA and subsequent papillary augmentation. Six studies were included in meta-analysis and showed that the intervention led to a pooled reduction percentage of 57.7% in BTA after 6 months. Although there were clinical diversities between the studies, all the studies applied the same concentration of HA (approximately 2%), 2-3 mm apical to the papilla tip in several intervals. Some degrees of relapse were reported in some studies. Conclusion: Within the limits of this study, this systematic review and meta-analysis showed that HA injection can serve as an efficient minimally-invasive treatment for small interdental papillary deficiencies. It is essential to conduct further randomized clinical studies with prolonged follow-ups in order to support this conclusion. https://fid.tums.ac.ir/index.php/fid/article/view/3732