Hyaluronic acid: A modern, noninvasive fix for embrasure spaces?
Key Highlights
- Hyaluronic acid gel injections are a promising, noninvasive treatment for reducing black triangles and improving periodontal esthetics.
- Clinical studies demonstrate significant improvements in papillary coverage, with some cases achieving complete regeneration within six months.
- Success depends on factors like gingival biotype, alveolar bone height, and filler concentration, requiring careful patient selection.
- Dental hygienists can play a key role in screening, educating, and potentially administering these treatments, expanding their scope of practice.
- Regulatory and clinical considerations are essential, as hyaluronic acid fillers are currently off-label for gingival use, necessitating further research and training.
Dental hygienists often hear concerns from their patients related to the esthetics of their smile. They want a brighter smile, longer teeth, or no black spaces between their teeth. These gaps are black triangles, and they’ve played a role in the increasing demand for cosmetic dentistry.1
The black triangles vary in size, can compromise the periodontium, and are formed from the lack of the interdental papilla. This can be from gingival recession, orthodontic movement, or tooth morphology.2,3
Although patients’ concerns about black triangles stem from cosmetic origins, other functional issues appear with the reduction of the interdental papilla,4 which is an integral portion of periodontal tissues. When its structure size is reduced, it will influence not only esthetics but also proper phonetics, food impaction, caries risk, biofilm accumulation, and successive periodontal disease, among other issues.4 This is a small structure, but it has a significant impact on the periodontium.
Dental providers recognize that gingival tissues cannot regenerate on their own. How can this structure be repaired? There are invasive solutions, such as connective tissue grafts or guided tissue regeneration. While there are a variety of techniques to fix the issue, they can be unpredictable and produce inconsistent results.5,6 With initial research supporting it, there is a modern, noninvasive treatment solution: hyaluronic acid gingival gel injections.
What are hyaluronic acid gingival gel injections?
Hyaluronic acid is a naturally occurring, high molecular-weight compound found in connective tissue, skin, and joints. The biocompatible, biodegradable, anti-inflammatory, hydrophilic, and viscoelastic properties of hyaluronic acid make it a promising compound not only for cosmetic purposes but also biological purposes.6
When hyaluronic acid is in gel form, it naturally clings to water, forms new collagen, and provides tissues with a fuller appearance and more structure. Restylane was the first FDA-approved dermal filler in 2003, with restylane-lidocaine receiving FDA approval in 2012.4 Though many hyaluronic acid fillers are FDA-approved for dermal use, they’re not yet approved for gingival injections and are considered off-label.
The research that initiated the use of these fillers for black triangles was conducted in 2009 and has since led to more research, with several randomized controlled trials and systematic reviews published.7 While there are varying results, there are consistent improvements in the reduction of the black triangle percentage, with much of the research resulting in statistically significant values from baseline to three months and six months.3,4
Clinical trial results
In the clinical trials selected for this article, there were clear improvements in papillary regeneration, with one study reporting three out of seven cases demonstrating complete papillary coverage and another study reporting 48% of the sites presenting with full coverage in six months.3,5
Before these fillers are fully integrated into practices, recognize that they’re not permanent and will need to be reinjected.2-4 The success of the fillers will also depend on specific factors, such as the patient’s gingival biotype, the length between the alveolar bone crest and contact point, and the concentration of the filler.4,7,8
When these factors are ideal, the outcomes will yield better results. Despite the limited incorporation into dental practices, there is evidence supporting the effects of these fillers for black triangles.
How hyaluronic acid fillers apply to dental hygienists
Compared to other dental clinicians, dental hygienists spend a significant amount of time with patients and are in an ideal position to screen patients for procedural candidacy. The dental hygiene team is educated on all things periodontics, so they understand not only the esthetic but also the functional and periodontal impact of black triangles.
A black triangle might indicate that a patient is struggling with sensitivity, biofilm accumulation, phonetic changes, and periodontal changes. While patients might not recognize the increase in their black triangle, hygienists will notice the tissue changes and can properly examine the patient for factors that would affect the efficacy of the fillers.4,7,8
Dental hygienists are licensed across 49 states to administer local anesthesia, and in 35 states to administer nitrous oxide.9 With the detection of interdental papillary loss and delivering local anesthesia, hygienists could play a part in administering hyaluronic acid fillers to suitable candidates.
An increasing trend in dental hygiene is the desire to administer neurotoxins, with Kansas and Oklahoma being the first states to allow hygienists to administer it under a doctor’s supervision.10 Since dental hygienists establish personal connections with patients and are efficient educators, they can clearly inform patients of the risks, benefits, and details of the procedural process.
Though there are still tight regulations for hygienists regarding cosmetics, this treatment modality could expand the functions of dental hygienists in the future. With the influence social media has on this procedure, it’s vital for dental hygienists to be educated about the treatment, especially because patients look to their hygienists for answers.
References
1. Emrani R. Socioeconomic determinants of demand for dental cosmetic treatments. Ind J Dent Res. 2023;34(1):36-39. doi:10.4103/ijdr.ijdr_390_22
2. Larderet A, Petit C, Huck O, Gegout PY. Effectiveness of hyaluronic acid injection in the reconstruction of interdental papilla: a systematic review. Oral Health Prevent Dent. 2025;23:279-290. doi:10.3290/j.ohpd.c_2057
3. Pitale U, Pal PC, Thakare G, Verma M, Dhakad S, Pandey R. Minimally invasive therapy for reconstruction of lost interdental papilla by using injectable hyaluronic acid filler. J Ind Soc Periodontol. 2021;25(1):22-28. doi:10.4103/jisp.jisp_19_20
4. Abdelraouf SA, Dahab OA, Elbarbary A, El-Din AM, Mostafa B. Assessment of hyaluronic acid gel injection in the reconstruction of interdental papilla: a randomized clinical trial. Macedonian J Med Sci. 2019;7(11):1834-1840. doi:10.3889/oamjms.2019.478
5. Kapoor S, Dudeja A. Derma fillers: ray of light in black triangles - a pilot study. Contemp Clin Dent. 2020;11(1):55-59. doi:10.4103/ccd.ccd_693_18
6. Sahu PP, Uppoor AS, Nayak SU. Hyaluronic acid: hope or hype in periodontics - a narrative review. J Ind Soc Periodontol. 2024;28(6), 614–620. doi:10.4103/jisp.jisp_476_23
7. Becker W, Gabitov I, Stepanov M, Kois J, Smidt A, Becker BE. Minimally invasive treatment for papillae deficiencies in the esthetic zone: a pilot study. Clin Impl Dent R el Res. 2010;12(1):1-8. doi:10.1111/j.1708-8208.2009.00247.x
8. Lee WP, Seo YS, Kim HJ, Yu SJ, Kim BO. The association between radiographic embrasure morphology and interdental papilla reconstruction using injectable hyaluronic acid gel. J Periodontol Impl Sci. 2016;46(4):277-287. doi:10.5051/jpis.2016.46.4.277
9. Scope of practice. American Dental Hygienists’ Association. September 23, 2025. https://www.adha.org/advocacy/scope-of-practice/
10. Botox for bruxism: a hygienist guide. American Academy of Facial Esthetics. November 20, 2025. https://facialesthetics.org/botox-for-bruxism-dental-hygienists-poised-to-offer-this-treatment/
About the Author
Melaina Reynolds, DH student
Melaina Reynolds is a second-year dental hygiene student at the Indiana University School of Dentistry with a growing passion for evidence-based practice and the evolving intersection between dental hygiene and cosmetic dentistry. With a keen interest in how aesthetics and oral health influence patient confidence and quality of life, she focuses her research on minimally invasive cosmetic interventions, patient-centered care, and emerging trends in dental materials and technology.
Lindsey Billing, MEd, BS, LDH
Lindsey Billing, MEd, BS, LDH, has been a licensed dental hygienist since 2011 in Indianapolis, Indiana. She has worked at a periodontal practice since licensure and is a Clinical Assistant Professor at the Indiana University School of Dentistry, Dental Hygiene Program. She teaches the periodontics and dental materials courses and is the clinical course director for the third-year dental hygiene students.