Clinical Evaluation of Gingivalstat Approach Compared to Conventional Esthetic Crown Lengthening on the Stability of The Gingival Margin in Patients With Altered Passive Eruption.

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.

Steps 1-6 as Active Comparator group + 7. Resin composite wil be placed on the cervical third of the teeth, following the CEJ anatomy, to act as a gingival stabilizer to guide the early remodelling of tissues.

8\. Removal of sutures and composite after two weeks.

Procedure: Esthetic Crown Lengthening using GingivalStat approach

1. Following the administration of local anaesthesia, a submarginal internal bevelled incision using 15c blade will be carried out, from canine to canine. The distance from the gingival margin will be based on how much soft tissue needs to be removed to meet the ideal tooth proportion.
2. Intrasulcular incision will be done in the buccal aspect and papilla region for removal of tissue collar.
3. A full thickness mucoperiosteal flap will be elevated using mucoperiosteal elevator, without bypassing the MGJ.
4. To obtain a 3 mm distance between CEJ and bone, osteoctomy wil be carried out from line angle to line angle using high speed hand piece with end-cutting bur.
5. Osteoplasty using round bur, maybe done to reduce bone thickness and obtain adequate anatomical profile.
6. After the flap is repositioned, interrupted sutures using Polypropylene 5-0 will be used to adapt and suture the flap in its new position.

Procedure: Esthetic Crown Lengthening

Conventional Esthetic Crown Lengthening

Esthetic Crown Lengthening using GingivalStat approach (composite stops)

Plazo: Baseline, immediate post operative, 2 weeks, 3 months and 6 months

Gingival margin position wil be measured using UNC periodontal probe + stent. Grooves will be made in the stent to standardize probe direction and localization. Each tooth will be assessed on the mesio-buccal, mid-buccal, and disto-buccal aspect at baseline, immediate post operative, 2 weeks, 3 months, and 6 months.

Plazo: Baseline, immediate postoperative, 2 weeks, 3 months and 6 months

Gingival margin position will be measured using Intra-oral digital Scan (IOS). It will be measured at baseline, immediately after surgery, 2 weeks, 3 months and 6 months. Scans will be superimposed to detect all changes throughout the follow up period.

Plazo: At 3 months and 6 months

It is based on seven variables: mesial papilla, distal papilla, soft-tissue level, soft tissue contour, alveolar process deficiency, soft-tissue color and texture. Each variable is assessed with a 2-1-0 score, with 2 being the best and 0 being the poorest score.

Plazo: At two weeks.

Readings will be recorded by the patient for the first 14 days after the surgery using the VAS which is a descriptive numerical rating scale of 0 to 10.

0 = No pain 1-3= Mild pain 4-6 = Moderate pain (bearable) 7-10 = Severe pain (unbearable)

Plazo: Two weeks, three months and six months

A 3-item questionnaire will be given to the patients to be answered using a 7-point answer scale for assessing their satisfaction with the whole procedure and the results of the procedure performed.

Plazo: At six months.

It will be calculated using an equation to correlate the procedural time, cost of the materials used against the clinical outcomes.

Plazo: At the surgery

It will be recorded in minutes using a stopwatch to measure the difference in the procedural time between the two groups.

Clinical Evaluation of Gingivalstat Approach Compared to Conventional Esthetic Crown Lengthening on the Stability of The Gingival Margin in Patients With Altered Passive Eruption. A Randomized Clinical Trial.