papillary reconstruction will be done by three techniques : injection of hyaluronic acid in the base of the papilla and booster doses can be required , injection of ALB-PRF which resorbs slowly and so longer effect the last technique is minimal invasive surgery which is a modification of beagle's technique

Interdental papilla (IDP) is the component of gingiva which occupies the cervical embrasure between proximal surfaces of the teeth. It is triangular when observed two dimensionally and pyramidal when viewed three dimensionally. Its shape, position, and presence are dependent upon the presence of underlying alveolar bone proper, proximal contact points, and area of adjacent teeth (1). This entity is also known as the interdental papillary house by Gonzalez et al (2), where the dimensions of the roof, floor and lateral walls of the interdental house help in maintaining the interdental papilla.

The function of the IDP is not only deflection of food debris but also acts as a barrier to protect the underlying periodontal tissues. A 'round cell infiltration' is found in the interdental papillae. The inflammatory infiltrate demonstrates a defense mechanism to the constant threat of bacterial invasion from dental plaque accumulation. The presence of the IDP also plays an essential role in aesthetics (3). The gingival unit is one of the key factors in maintaining esthetics and for this reason the presence of a normal sized and harmonically shaped IDP becomes crucial (4). It creates visual harmony between the gingiva topography and surrounding gingiva contours (5). Its deficiency can lead to a negative impact in the oral health-related quality of life and self-esteem for the patient.

If there is any defect of alveolar bone proper or adjacent tooth contact, the IPD will fail to sustain its original form resulting in empty space between teeth. This space is commonly referred as a black triangle or open gingival embrasure as a result of deficiency or loss of papilla beneath the contact points. This black triangle has many negative consequences as unpleasant appearance while smiling, food impaction and phonetic problems (6). Numerous risk factors lead to the development of this problem (7). These factors include aging, periodontal disease, loss of height of the alveolar bone relative to the interproximal contact, length of embrasure area, root angulations, tooth loss, faulty oral hygiene procedures, interproximal contact position, and triangular-shaped crowns (8, 9).

Due to its aesthetic impact and mandatory role, dentists always in a continuous challenge to restore the lost pink triangle because this region is characteristically narrow making surgery more difficult and limiting the blood supply to the associated soft tissue (5,10). Treatment options for papillary reconstruction could be surgical, non-surgical or ortho-restorative in nature which vary in long term success rates.

Currently the standard procedures for papillary reconstruction (PR) are sulcular releasing incisions, coronal flap movement and connective tissue graft (CTG) being replaced interproximally. Connective tissue graft with a coronally advanced flap is preferred more frequently than others. Despite its advantages, the presence of a second wound site and variable PR outcomes still leads the clinicians to search for alternatives (10).

Recently all the studies are directed toward less invasive techniques to minimize post operative discomfort, decrease number of surgical sites & improve patient satisfaction. These techniques include non-surgical injection of hyaluronic acid or platelet rich fibrin (PRF) and minor surgeries such as placement of PRF on semilunar incision or pedicle grafts as it will be described later.

Hyaluronan (HA) is a component in extracellular matrix that regulates the cells behavior, tissue environment and tissue regeneration. It has been extensively used in aesthetic products. Recently, HA has been introduced as a less invasive procedure to treat black triangle (11). The currently available injectable hyaluronic acid gels are polymers that are formulated by crosslinking hyaluronic acid produced by Streptococcus species. Injection is done on multiple sessions to ensure complete papilla regeneration (5).

Platelet rich fibrin is recommended as a supportive or alternative to CTG in periodontal surgery to benefit from its dense fibrin structure and growth factors content, that enhance wound healing and tissue formation (10). It plays a vital role in differentiation of precursor cells for regeneration of interdental papilla (12). Notably, involvement of PRF in neo angiogenesis could potentially reduce necrosis and shrinkage of the surgical flap (13, 14).

Injectable albumin platelet rich fibrin (Alb-PRF) is a recent form of PRF which overcomes limitations of previous forms such as rapid absorption. This modified biocompatible biologic product has a long degradation period that accelerates papilla regeneration by the continuous release of growth factors and increases the absorption time from two weeks to more than four months. Albumin gel is formed by heating the platelet-poor plasma (PPP) and mixed with liquid PRF to form Alb-PRF gel (15).

Modified Beagle's technique is another novel minimally invasive surgical approach for restoring lost IDP. The standard Beagle's technique includes partial thickness incision along the line angles of adjacent teeth on the palatal aspect then it's elevated and folded on the labial aspect. So our technique is a variant of Beagle's technique to achieve soft tissue augmentation of anterior interproximal space, without requiring a second surgical site. It consists of a small pedicle flap elevated from labial side and folded upon itself. Furthermore, this procedure is less time-consuming and surgically more simple (7).

For all methods to be successful, surgical procedures must maintain the integrity of interproximal tissues (16). Currently there are no randomized clinical trials comparing these minimal invasive methods and that's what we will explore in this study.

Inclusion Criteria:

• 1. Age: 20 to 50 years. 2. Class 1 and 2 inter dental papilla loss according to Nordland & Tarnow classification (17).

  3. Adequate attached gingiva (minimum 3 mm). 4. Stage 1or 2 periodontitis (18).

Exclusion Criteria:

• 1. Smokers. 2. Chronic systemic diseases. 3. Drug usage. 4. High frenum attachment. 5. Diastema. 6. Pregnancy and lactation. 7. Stage 3 & 4 periodontitis (18). 8. Noncompliance with oral hygiene measures.