Treatment Off Gingival Recession Defects Using a Xenogenic Acellular Dermal Matrix Compared to Connective Tissue Graft.

Inclusion Criteria: * Patients \> 45 years, postmenopausal women (ie with amenorrhea for more than a year). * Subject with bilateral Miller class I or II recessions defects * non smoking patients * patients having read and understood the information note on the study and signed the informed consent form. * patients affiliated to the social security system. Exclusion Criteria: * Patient with absolute contra-indication for dental surgery: valvular heart disease at risk of infectious endocarditis, recent myocardal (≤ 12 months), organ transplants, recent placement of a coronary stent (≤ 12 months), transient ischemic attacks recurrent, cardiovascular instability, uncontrolled epilepsy, rheumatic fever. * Patient with metabolic bone disease (Paget's disease, osteomalacia, osteogenesis imperfecta) * Patient with an ASA score ≥ 3. * Patient with absolute contra-indication to dental surgery * Patient with severe hematologic disease * Patient with I or type II diabetes * Patients with previous or current acute illness or severe chronic cardiovascular, renal, hepatic, gastrointestinal, allergic, endocrine, neuro-psychiatric, considered by the investigator to be incompatible with the conduct of the study. * Patients treated with retinoids, oral bisphosphonates, oral anticoagulants or anticonvulsants. * Patient have or have had cancer of the upper aerodigestive tract treated by radiotherapy. * Patient taking a steroidal or non-steroidal anti-inflammatory, anti-cancer or immunosuppressive chemotherapy in the last 6 months. * Patient monitoring considered difficult by the investigator. * Patient with poor oral hygiene incompatible with oral surgery. * Patients with periodontal disease unstabilized * Patient with oral dermatitis or adverse occlusion. * Patient with an acute or chronic infection of the surgical site (osteomyelitis). * Patient with a known allergy to collagen * Patient with autoimmune disease * Patient with a linguistic or mental incapacity to understand information * Patient younger than 45 years old * Patient trust under curatorship or judicial protection * Patients aged over 45 premenopausal. * Patient participating in another clinical study.