Aim: The aim of this randomized clinical trial is to evaluate the use of the porcine acellular dermal matrix (PADM) for the treatment of RT1 localized gingival recessions.

Material and methods: Forthy patients (n=20) with RT1 localized gingival recessions with height ranging from 3 to 5 mm with and at least, 2mm of keratinized tissue width will be selected to participate in the study. Patients will be allocated randomly in two treatment groups: Coronally advanced flap (CAF) or coronally advanced flap associated with the porcine acellular dermal matrix (CAF+ PADM). The clinical parameters evaluated at the baseline, 6 and 12 months will be: Plaque index (IPL); gingival index (GI); relative gingival recession height (RGRH); gingival recession width (GRW); probing depth (PD); relative clinical attachment level (RCAL); keratinized tissue height (KTH); keratinized tissue thickness (KTT); papilla height (PH). Evaluations will be made by the professional and the patient regarding dentin hypersensitivity (HD) (Schiff and VAS scales respectively), aesthetics (RES and VAS scales, respectively) and patient's centered outcomes, through the questionnaire referring to the OHIP-14.

Descriptive statistical analysis will be expressed as mean ± standard deviation (SD), median, quartiles, percentages and confidence intervals (95% CI). To analyze the normality of the residue, the Shapiro-Wilk test will be performed. Then, the Wilcoxon test will be applied to compare the periodontal parameters and a quality of life, before and post-treatment. Correlations between parameters and dental hypersensitivity will be analyzed through Spearman's test. Key words: Gingival recession, Root coverage, Biomaterial, Acellular dermal matrix.

Inclusion Criteria:

• RT1 localized gingival recessions with height ranging from 3 to 5 mm;
• 2mm or more of keratinized tissue width ;
• Probing depth less than 3mm;
• Plaque and gingival index less or equal to 20%.

Exclusion Criteria:

• Smokers;
• Pregnants;
• Nursing;
• Patients with diabetes mellitus or another condition that interfere in the tissue repair
• Patients who use drugs or medications that interfere in the tissue repair;
• Allergies to any composition of the devices of the study.