Inclusion Criteria:  have at least one tooth (from the central incisor to the second permanent molar) to be extracted and replaced with an endosseous implant; no need of a temporary prosthesis; availability to participate to the follow-up; sign the study informed consent and consent to data treatment;  Exclusion Criteria:  less than 20 years; known allergy to collagen or bone graft material; contraindications to implant therapy; ongoing bisphosphonate-based therapy; ongoing high-dose corticosteroid therapy; relevant co-morbidities of the maxillary bones that interfere with bone remodeling (degenerative bone diseases, osteomyelitis at the extraction site or surrounding areas, subacute mandibular osteitis, local microvascular disorders); smoking; pregnancy; metabolic diseases (diabetes, hyperparathyroidism); systemic bone diseases;