The efficacy of various bone augmentation procedures for dental implants: a Cochrane systematic review of randomized controlled clinical trials.

To test (a) whether and when bone augmentation procedures are necessary and (b) which is the most effective augmentation technique for specific clinical indications. Trials were divided into 3 categories: (1) major vertical or horizontal bone augmentation (or both); (2) implants placed in extraction sockets; (3) fenestrated implants.