Is there clinical evidence to support alveolar ridge preservation over extraction alone? A review of recent literature and case reports of late graft failure

Since its introduction in 1998, alveolar ridge preservation has become a popular technique, currently accounting for approximately 29% of all procedures involving bone substitute materials. The global cost of bone substitute materials for alveolar ridge preservation is estimated at $190 million annually and is expected to rise by approximately 11.4% per year. Numerous randomised controlled trials have compared alveolar ridge preservation to extraction alone. A recent Cochrane review reported that, in terms of socket dimensional change, the mean difference between alveolar ridge preservation and extraction alone is 1.18 mm horizontally and 1.35 mm vertically. The clinical impact of this is uncertain, for there is no significant difference in the need for graft procedures at implant placement between ridge preservation and extraction alone. There are no randomised controlled trials comparing aesthetic or functional outcomes. A systematic review of the histological outcomes of ridge preservation demonstrates that, compared to extraction alone, many bone substitute materials can significantly delay the bone healing process. No bone substitute material achieves statistically more new bone formation than extraction alone and many commonly used materials achieve significantly less bone formation. Grafted sites can demonstrate high levels of residual graft and granulation tissue. In the absence of good-quality clinical evidence to support alveolar ridge preservation, the technique must be questioned as the treatment of choice at extraction sites. This paper assesses recent systematic reviews and presents two case reports of late graft failure.