The Impact of Immediate Implant Placement on Alveolar Ridge Preservation Techniques

Hypothesis/Aims Primary hypotesis Placing an immediate implant into a fresh extraction site plus a bone substitute filling and a matrix covering could negatively modify the healing patterns and thus the tissue morphology of the ridge site with regard to: * clinical hard tissues dimensions (bone width and height, bone volume) * clinical soft tissues dimensions (soft tissues volume, keratinized tissues width and thickness, muco-gingival junction position's modifications, gingival color and texture,) Secondary hypothesis. Placing an immediate implant into fresh extraction site plus a bone substitute filling and a matrix covering could negatively influence tissue morphology of the preserved site with regard to: * clinical hard tissues dimensions (bone width and height, bone volume) * clinical soft tissues dimensions (soft tissues volume, keratinized tissues width and thickness, muco-gingival junction position's modifications, gingival color and texture,) Aims: The first aim of this study is to evaluate the possible impact on hard and soft tissue morphological changes of placing an immediate implant in post-extraction site treated by a bone substitute filling and a matrix covering. The second aim of this study is to compare hard and soft tissue morphological changes in a spontaneous healed extraction site versus a fresh extraction site treated by immediate implant placement plus a bone substitute filling and a matrix covering