%0 Journal Article %T Bone Morphometric Evaluation around Immediately Placed Implants Covered with Porcine-Derived Pericardium Membrane: An Experimental Study in Dogs %A Ryo Jimbo %A Charles Marin %A Lukasz Witek %A Marcelo Suzuki %A Nick Tovar %A Ioana Chesnoiu-Matei %A Irina Florentina Dragan %A Paulo G. Coelho %J International Journal of Biomaterials %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/279167 %X Objective. To investigate whether porcine-derived bioresorbable pericardium membrane coverage enhances the osseointegration around implants placed in fresh extraction sockets. Study Design. Twenty-four commercially available endosseous implants were placed in the fresh extraction sockets of the mandibular first molar of mature beagles ( ). On one side, implants and osteotomy sites were covered with porcine-derived bioresorbable pericardium membranes, whereas on the other side, no membranes were used. After 6 weeks, samples were retrieved and were histologically processed for histomorphometric analysis. Results. The histological observation showed that bone loss and soft tissue migration in the coronal region of the implant were evident for the control group, whereas bone fill was evident up to the neck of the implant for the membrane-covered group. Bone-to-implant contact was significantly higher for the membrane-covered group compared to the control group, 75% and 45% ( ), respectively. Conclusion. The experimental membranes proved to regenerate bone around implants placed in fresh extraction sockets without soft tissue intrusion. 1. Introduction The regeneration and healing of bone is a gradual process, and are constantly prone to soft tissue infiltration, particularly in large defects. In order to enhance the healing process, and at the same time, to prevent the migration of unwanted cells, it has been suggested that segregation of the defects via a membrane barrier is effective [1, 2]. Membranes also sustain blood clots in place and allow time for bone forming cells to reconstruct bone unobstructed, which is beneficial for applications such as implant placement in fresh extraction sockets. The surgical and restorative advantages of placing dental implants in fresh extraction sockets have been discussed clinically by various authors [3¨C7] with a sufficient number of in vivo studies supporting that successful osseointegration can be achieved in these situations [8¨C12]. The so-called immediate implant placement is less invasive and potentially more efficient than the classic approach, where multiple surgeries may be needed if using a graft material for the initial bone healing process. However, one of the surgical limitations of an immediate implant placement procedure is that often a socket presents dimensions that may be greater than the diameter of a conventional implant, which at many times results in the presence of a substantial gap between the implant and the socket wall [13] and resorption of the buccal bone wall [14]. It has been proposed that %U http://www.hindawi.com/journals/ijbm/2012/279167/