Inclusion Criteria:  Patient requiring oral surgery Patient with a bleeding requiring the use of an adjuvant hemostatic Patient implanted with HEMOCOLLAGENE® in dental surgery. Patient who signed his informed consent form  Exclusion Criteria:  Inform Consent not signed Patients with acute oral infection. Patients with an unstable hemodynamic state (acute and/or chronic cardiovascular pathology, low arterial pressure, cardiac rythm problem) Pregnant and / or breastfeeding patients. Patient with hypersensitivy or allergy to bovin collagen