The aim of this study is to evaluate the volume of madibular bone after placement of a xenograft in a fresh extraction socket in human. The surgery protocol is flapless, and the teeth are mandibular premolars or molars leaving sockets with 4 walls intact or at least 3 walls intact and the buccal wall at 80% . This study will include 35 patients.

Primary objective :

Estimate the percentage of loss of bone volume and the percentage thickness loss of the buccal and palatal cortical for patients who underwent bone volume preservation technology and conservation of the vestibular cortical by guided bone regeneration using a material slow absorption in the molar areas and premolar.

Secondary objectives:

Compare the percentage of loss of bone volume and the percentage loss of thickness of the buccal and palatal cortical patients who underwent a preservation technique, the upgrading data of mandibular posterior region without fillers described in the literature.

Methods :

After tooth extraction of a premolar or molar in mandibular flapless technique, guided bone regeneration is carried out. The cell is filled by a slow absorption material (Xenograft common use). The regeneration space is maintained by a resorbable membrane. To protect the membrane without tissue motion (technical flapless) placing a three-dimensional collagen matrix graft substitute gingival (Muccograft®) will be used. A CBCT preoperative be performed to verify the integrity of cortical and measure the height and width of the residual cavity. caliper measurements at the foot will also be performed during surgery in order to integrate also the thickness of the bone tables and gingival thickness.

After healing of the graft, the pre-implant scan performed at six months postoperatively will measure the height and width of the grafted cell, to compare measurements and evaluate the dynamics of alveolar resorption

Inclusion criteria general

• with a unit or avulsion and ROG including 2 adjacent teeth maximum premolars
• aged 18 to 75
• has given its no objection to participate in research Inclusion criteria patient
• Patients can meet the demands of implant treatment (attendance, hygiene)
• Patients showing no indication against-General to surgery

Exclusion criteria patient

• Patient with against-indication for implant treatment. Whether for medical reasons against showing the pre and implant surgery, or local reasons a total loss of vestibular cortical unstabilized periodontal disease or aesthetic cons-indication.

Exclusion criteria general

• Inability to maintain a good level of oral hygiene and good cooperation.
• Higher tobacco consumption has 10cig / day
• Acute dental infection

NC