In 52 patients, single anterior teeth were extracted and replaced by immediate implants. The peri-implant gap was left either untreated (control) or was grafted and covered with a membrane (test group). After 12 months the horizontal bone resorption was significantly lower in the test group (test sites: 0.69 ± 0.68 mm, 8.13%; control sites: 1.92 ± 1.02 mm, 21.62%; P = .001), and there was less reduction in ridge height (test sites: 0.58 ± 0.77 mm; control sites: 1.69 ± 1.74 mm; P = .004). Ridge preservation considerably limited the amount of horizontal and vertical soft tissue alterations when compared with implant placement alone.