“…One of these RCTs involving 40 patients showed a reduction of 43% in the spontaneous healing group compared to 18% of xenograft groups at 1 mm below the crest (Jung et al., ). Another RCT with 48 anterior extraction sockets assessing spontaneous healing vs alveolar ridge preservation with xenograft demonstrated a considerable reduction in the amount of horizontal and vertical bone resorption in the xenograft group (Cardaropoli, Gaveglio, & Cardaropoli, ). A recent RCT compared extraction sockets that have been preserved with the same xenograft but covered either by a porcine collagen matrix or an epithelial connective tissue graft.…”