The objective of this study is to investigate the use of human amnion chorion membrane (BioXclude®) as an exposed barrier in ridge preservation and whether the intentional exposure of this membrane to oral environment will adversely affect ridge healing, dimensions, and bone vitality. This is a randomized clinical study.

Alveolar ridge resorption is common sequelae following tooth extraction and presents a challenge for implant placement. The width of the alveolar ridge is known to be resorbed to 30% and 50% of it is original dimension after 3 and 12 months respectively when the extraction socket was left to heal on its own(Schropp, Wenzel et al. 2003). Clinical studies have investigated the socket augmentation technique to prevent the collapse of socket dimension after extraction, and to maintain the ridge width and height for implant placement. This technique includes grafting the socket with bone particulate and then covering the grafted socket with a barrier membrane. (Iasella, Greenwell et al. 2003; Wang and Tsao 2008). In socket augmentation, the role of bone particles is to induce the formation of bone or to provide a scaffold for the new bone formation. The role of the membrane is to keep bone particles within the socket and to exclude the epithelial and connective tissue cells from populating the extraction socket, thus allow the bone cells populating the socket and forming new bone. (Smukler, Landi et al. 1999). The ideal membrane should have no immunological responses, facilitate tissue integration, maintain the clot space, and have good handling properties (Scantlebury 1993; Rakhmatia, Ayukawa et al. 2013). A variety of resorbable and non-resorbable barrier membranes used in socket preservation have been reported in clinical studies. They have clearly shown variable rates of new bone formation prior to implant placement.(Smukler, Landi et al. 1999) (Fotek, Neiva et al. 2009). A xenograft collagen membrane was used in several clinical studies for socket augmentation (Sevor and Meffert 1992; Sevor, Meffert et al. 1993; Iasella, Greenwell et al. 2003; Wang and Tsao 2008).

Another type of resorbable membrane that has been investigated for socket augmentation is the allograft placental membrane. Processed, dehydrated and sterilized human placental amnion chorionic membrane (ACM) has been successfully used in many clinical applications in soft tissue repair and regeneration. (Trelford and Trelford-Sauder 1979; Nakamura, Koizumi et al. 2003).

ACM have also been used in human clinical studies to assess gingival healing and bone formation in augmented sockets and osseous defects.(Wallace 2010; Holtzclaw 2011; Wallace 2011).

In this study, the investigators aim to compare two resorbable membrane (allograft placental-BioXclude versus xenograft collagen- Mem Lok) in order to find out whether one of these membrane could provide better soft tissue healing and better bone quality before implants are placed. Both membranes are FDA approved and tested for human use. Their proposed use in this study is FDA approved.

Inclusion Criteria:

• must have an unsalvageable tooth with extraction planned with delayed implant
• extraction sockets must have intact buccal and lingual cortical plates

Exclusion Criteria:

• completely endentulous
• plan for a full mouth tooth extraction
• radiation therapy
• uncontrolled systemic disorders
• acute odontogenic infections
• smoking >10 cigarettes/day
• taking anti-resorptive meds
• pregnant or may become pregnant