Purpose: The aim of this clinical study was to assess horizontal width changes in grafted and ungrafted sites after bone expansion and implant placement. Materials and Methods: Twenty-three patients were included in this prospective study. Each patient required extraction of two teeth and replacement with implants. After dental extraction in 23 alveoli (group 1), a collagen sponge was used to cover fresh sockets, and the remaining 23 alveoli (group 2) were grafted with corticocancellous porcine bone. Three months after extraction, bone expansion was performed in each site, and 46 dental implants were placed. To evaluate tissue volume changes, the variations in width of the buccal ridge were recorded with a periodontal probe immediately after tooth extraction, 3 months later (before implant placement), and 3 months after implant placement. Results: In group 1, at 3 months after implant placement, mean volume changes of +1.6 ± 0.8 mm for incisors and canines, +1.4 ± 0.5 mm for premolars, and +0.8 ± 0.5 mm for molars were seen. In group 2, mean changes of +1.5 ± 0.8 mm for incisors and canines, +1.3 ± 0.3 mm for premolars, and +2.8 ± 0.6 mm for molars were observed. Statistically significant differences were found only for molars. Conclusions: In both groups, incisor, canine, and premolar sites showed no differences in volume changes, but statistically significant differences were found between molars in the two groups; the biomaterial graft prevented collapse of the large defects and significant volume loss. Schlagwörter: biomaterial, bone remodeling, fresh socket