 - Since the gingival recession defects are non-space making, it may be difficult using the membrane technique alone, and hence, the use of a graft material underneath the membrane may help to resolve this problem. Root coverage tended to be better with the addition of demineralized freeze-dried bone allograft DFDBA. These allografts prevent the collapse of membrane into the defect, stimulate the proliferation of osteogenic progenitor cells, and are thus, capable of promoting regeneration of attachment apparatus. 