When performing crown lengthening surgery, especially in the esthetic zone, the positional stability of gingival tissues is considered a prime important goal. The rebound of gingival margins after surgery can result in compromising the esthetic outcome and patient satisfaction. It was proven throughout the literature that there are many factors that may influence the stability of gingival margin position after surgery such as: the surgical technique being performed, experience of the clinician, periodontal phenotype and distance of flap with respect to the alveolar crest.

A "gummy smile" or excessive gingival display (EGD) is when at least 3-5 mm of gingiva is visible. It is viewed as unnatural or unsightly, and in order to have the best outcome, cosmetic periodontal recontouring is frequently necessary. It is considered the treatment of choice for excessive gingival display, or "Gummy smile,". Many causes of gummy smiles have been found, including altered passive eruption, short upper lip, dentoalveolar extrusion, abnormal vertical bone growth, and a combination of some of these.

Altered passive eruption is when the gingival margin is located incisal to the cervical convexity of the crown and away from the cemento-enamel junction of the tooth. It is considered the most frequent related factor, accounting for between 12.1 and 35.8% of excessive gingival display cases that have been identified, according to evidence.

Considering esthetic crown lengthening (ECL) surgery, the goal is to restore the gingival harmony and symmetry by reestablishing the proper clinical crown length. However, stability of the periodontal tissues after ECL is a crucial aspect that can be jeopardized the treatment outcome of the treated region. In particular, gingival margin rebound can impair aesthetics and have an impact on the health of periodontal tissue

Predicting the amount of tissue rebound after esthetic crown lengthening surgery is still controversial. According to literature, there is a tendency to have a gingival regrowth from the immediate postoperative level for up to 3 months. It has been also confirmed that rebound of gingival margin most likely occurs during the first three months following surgery. Another study found that the gingival margin had coronal migration may continue for up to 6-12 months after surgery.

Based on current evidence, gingival margin rebound is a major issue that happens after performing crown lengthening surgery. To avoid this, GingivalStat approach has been proposed to guide the tissue after surgery to remodel early at a predetermined position and avoid the re-growth of gingiva in a coronal direction. It appears to be producing earlier stability. The current study aims to investigate the influence of GingivalStat following crown lengthening versus conventional crown lengthening, in terms of stability of gingival margin.

Inclusion Criteria:

1. Patients with Altered Passive Eruption Subtype B presenting altered alveolar bone crest-CEJ relationship according to Coslet's et al. classification.
2. Patients free of systemic diseases.
3. Patients aged between 18 to 60 years old.
4. Patients maintaining good oral hygiene with full-mouth plaque and bleeding scores <15%.
5. Patients should be committed to the post-operative care regime, including oral hygiene practices, and follow-up visits.

Exclusion Criteria:

1. Areas in which the remaining amount of keratinized gingiva after the submarginal incision will be less than 3 mm.
2. Patients with periodontal disease.
3. Smokers.
4. Pregnant women.
5. Patients on medication that may interfere with healing (corticosteroids, bisphosphonate, Chemo/radiotherapy)