This research aims to investigate the effectiveness of non invasive application Hyaluronic acid gel injection versus minimally invasive surgical approach using multilayer L-PRF both clinically and radiographically as a suitable treatment modality for interdental papillary deficiency.

A total of 20 patients recruited from the outpatient clinic of Oral Medicine, Periodontology and Oral Diagnosis department, Faculty of Dentistry, Ain-Shams University and seeking treatment for black triangles for esthetic reason. Patients meeting the eligibility criteria are equally and randomly allocated in two different groups. group one Included 10 patients who received interdental papillary reconstruction using multiple layers of L-PRF. Group two Included 10 patients who received interdental papillary reconstruction using Hyaluronic acid gel injection. In the follow-up phase, patients were recalled after 3 and 6 months from intervention where clinical re-measurement of the black triangles and standardized digital clinical photographs and radiographs are done. Black triangle height and surface area was measured and other clinical parameters (Modified papillary bleeding index, Gingival index, clinical attachment level and periodontal probing depth) were assessed at baseline, 3 months and 6 months periods. patient satisfaction was evaluated using the patient satisfaction questionnaire (PSQ-18, short form) at baseline. pain and discomfort was evaluated using Numerical rating scale (NRS) at baseline, 3 months and 6 months periods. Global esthetic improvement scale (GAIS) was evaluated at 3 months and 6 months periods.

Inclusion Criteria:

1. Both genders aged from 18-45 years.
2. Systemically healthy patients.
3. Patients with IDP loss class I or II of esthetic zone in upper and lower anterior and premolar teeth according to Nordland and Tarnow's classification (Class I: Presence of the tip of the papilla between interdental contact point and the interproximal CEJ)
4. Presence of sufficient interdental alveolar bone (i.e. the vertical distance from the interdental contact point to the crest of the interdental bone is ≥ 5 mm) that was confirmed clinically by bone sounding.
5. A band of keratinized tissue should be present around the test teeth ≥ 2 mm
6. Periodontal phenotype of the area to be treated is ≥ 2 mm in thickness. Surgical reconstruction of IDP is influenced by gingival tissue phenotype, outcome of papilla reconstruction is better in cases with a thick gingival unit
7. Patients with good oral hygiene and caring about esthetics and concerned to go through the management of "black triangles" by interdental papillae reconstruction in esthetic zone.

Exclusion criteria:

1. Teeth with acute periapical pathosis.
2. Patients with poor oral hygiene, incompliance to treatment and persistence of gingival inflammation after phase I therapy.
3. Pregnant and lactating females.
4. Patients having para-functional habits or local causes as, malocclusion, interdental spacing, rotation, inclination or crowding.
5. Smokers, alcoholics or drug abusers.
6. Vulnerable group of patients, orphans, handicapped, prisoners or mentally retarded patients.