Guided Bone Regeneration (GBR) is a surgical procedure that involves the addition of a bone grafting material with a collagen membrane to increase the amount of bone where bone loss has occurred.  When a tooth or teeth are extracted conventionally, bone loss naturally occurs.  This bone loss prevents the proper placement of dental implants.  Therefore, bone grafting (GBR) must be carried out to increase the amount of bone in the area before the implant is placed.