ANALISYS OF MULTIPLE GINGIVAL RECESSION TREATMENT WITH SUBEPITHELIAL CONNECTIVE TISSUE GRAFT REMOVED FROM PALATAL AREA WITH PREDOMINANCE OF LAMINA PROPRIA AND PREDOMINANCE OF SUBMUCOSA: CLINICAL EVALUATION AND LASER DOPPLER FLOWMETRY

This will be a randomized, double-blind, split-mouth clinical trial lasting 12 months. Participants will be selected from the Department of Periodontology of the Faculty of Dentistry of Bauru (FOB-USP). The sample will consist of systemically healthy individuals aged between 18 and 70 years. Patients will be included in the study if they meet the following inclusion criteria: (1) clinical diagnosis of multiple gingival recessions with at least one gingival recession ≥ 2 mm, including canines and premolars; (2) Miller class I and II gingival recession areas; (3) non-abrasive, erosive or carious root surfaces (4) unrotated, non-extruded and non-movable teeth (5) systemically healthy patients without contraindication to periodontal surgical procedures. The exclusion criteria will be: smokers, pregnant women, patients with a history of periodontal disease or recurrent abscess formation, patients previously submitted to surgical procedures for root coverage, patients taking anti-convulsant drugs, antihypertensives, contraceptives or immunosuppressors, patientes with low oral hygiene (plaque and bleeding index over 20%). The experimental protocol will be sent to the FOB-USP Human Research Ethics Committee for evaluation. Participants will receive detailed information about the study and will sign the Informed Consent Form after understanding all the steps of the research. All selected patients will be submitted to basic periodontal procedures (scaling, root planning, coronary polishing and oral hygiene instructions) before performing the surgical procedures. Patients should present plaque index and bleeding ≤ 20% throughout the study period.

Surgical Procedures

The experimental groups (A and B) will be treated through the association of subepithelial connective tissue graft (SCTG) and coronally advanced flap. Each individual will receive the types of treatment, randomly assigned to the right or left side. Group A will receive the submucosal predominant area for SCTG (removed from the anterior region of the lateral palate, more deeply) by the double-blade technique (Harris, 1997). This collection method allows a uniformity of the SCTG with standard thickness (1.5mm). Thus, the scalpel cable with double blades (1.5mm distance) will be used. The initial horizontal incision will be made on the palate, preserving 1-1.5 mm from the gingival margin of the teeth, until the complete deepening of the number 15C blades in the necessary extension previously defined for the receiving area. Internal vertical incisions will be performed for both sides of the horizontal incision and at the base of the graft to enable the SCTG removal. After the graft removal, the epithelial portion is extracted for subsequent stabilization of the graft to the recipient site.

Group B will be the one who will receive a graft whit a predominance of lamina propria (removed from the posterior region of the lateral palate, more superficially) by the technique of the deepithelialized graft. Two horizontal and two vertical incisions will be performed on the palate according to the extension needed for the recipient area, preserving 1-1.5 mm from the gingival margin of the teeth. These incisions will be made perpendicular to the palatine dome. Subsequently, for complete removal of the epithelial graft, an incision will be made with the 15 C blade, parallel to the palatal surface. The graft should be approximately 2 mm thick and after removal of the entire epithelium, the thickness should be 1.5 mm, measured with the anesthetic needle with endodontic stop and a digital pachymeter. The removal of the epithelium will be performed with the aid of reflector light (epithelium is firmer and more rugged and connective tissue, more flexible and soft) parallel to the surface of the graft. The difference in light reflection (epithelium reflects more than connective tissue) allows one to distinguish whether it has been removed (Zuchelli et al., 2010).

The width of the graft will be calculated according to the amount of tissue needed to cover the exposed roots plus mesial and distal 3mm and the amount of tissue required for the biopsy. The graft height will be the distance from the enamel cement junction (ECJ) to the buccal bone crest (Zuchelli et al., 2010). A small biopsy of the grafts (approximately 2mm x 6mm) will be removed for histomorphometric analysis. The donor area will be sutured with silk thread 4.0.