Multiple Gingival Recessions Root Coverage Using Coronally Advanced Tunnel Technique Combined with a Xenogenic Dermal Matrix (Novomatrix®): a Randomized Clinical Trial

Study design In the pre-surgical clinical evaluation periodontal measurements were registered at baseline and during the follow-up period: periodontal probing depth (PPD), clinical attachment level (CAL), width and length (mm) of the GR, type of GR, amount of attached gingiva (mm), depth of vestibule (mm), interdental papilla height (mm), non carious cervical lesions, visual LAC detection, gingival thickness (mm) and gingival phenotype (translucency of the periodontal probe). Intraoral photographs always showing a frontal view of the treated area were taken. Moreover, all patients received supragingival scaling and crown polishing. Patient were instructed to rinse with 0.12% Chlorhexidine, 2 times a day for 1 minute starting one week prior to the surgery. Local etiological factors in the area of treatment were controlled or modified, such as the removal and change of overflowing seals, the polishing of restorations, the adjustment of margins. In cases where the cement enamel junction is not clearly detected a reconstruction of this with resin was carried out. Finally, prior to surgery, anti-inflammatory treatment were prescribed to the patient from the day before surgery with Ibuprofen 400 mg, 1 every 8 hours for 7 days

Clinical Procedures:

Prior to surgical procedure, a sealed envelope was opened with the treatment modality (randomization table). Local infiltration anesthesia was performed on both sides (buccal and lingual/palatal) of the affected area. The surgical protocol was performed following the tunnel technique described by Allen (1994) and using microsurgical instruments for periodontal plastic surgery [KPA Allen, PPAELA, tunelisation knife black line, (Hu Fredy)]. The flap was exposed using a modified coronal tunnel technique with partia papillae elevation.

The protocol was started with intra-muscular incisions with an intrasurcular scalpel (KPA Allen) in each of the treated teeth. Elevation of the flap was performed, using the Allen elevator (PPAELA), till the mucogingival line. After reaching this limit, a partial thickness dissection started using the modified Orban knife, until full tension of the flap was eliminated. The interdental papilla's was partially elevated, without being cut from their alveolar base in order to be able to coronally advance the flap to a coronal position free from tension. The flap was extended one tooth mesial and one tooth distal of the treatment area. The separation of the flap from small muscle fibers and bundles of collagen fibers was carefully carried out until the flap can passively be positioned at least 1mm above the cement enamel junction of all the involved teeth, in order to ensure the passive reposition of the flap and the posterior suture free of tension. After assuring the adequate extension of the tunnel, preparation and decontamination of the roots was carried out using Gracey curettes, eliminating the superficial cement surface in relation to the exposed root portion in order to achieve a smooth and flat surface.

All clinical procedures were performed by the same experienced surgeon who was blind to the treatment modality. All evaluations, procedures and controls will be performed in the dental center and pavilions of the Clinic of the Universidad de los Andes and the International University of Cataluña, were two experienced peridontontis (A.C and A.P) will perform the MCAT.