A surgically implantable containment member for maintaining a bone augmentation material in a desired location and/or configuration following implantation in a human or other mammalian patient, in which the containment member is made of a natural membrane, such as pericardium, isolated from an animal donor and processed to avoid inflammation or tissue rejection, and a method of bone augmentation using such a containment member. In a particularly preferred embodiment, the containment member has a window which rapidly dissipates upon exposure to bodily fluids after implantation to expose bone augmentation material contained within the containment member to an adjacent bone to be augmented.
