The aim of this histomorphometric study was to compare the outcome of sinus floor augmentation procedures using bovine bone mineral and a xenograft enriched with gelatin and a polymer. In 20 patients a single sinus floor elevation procedure with a lateral window approach was performed. In half of the patients, sinuses were grafted with a deproteinized bovine bone mineral-DBBM (control group)-while in the remaining 10, a xenograft enriched by polymer and gelatin-NBS (test group)-was applied. In the DBBM group, histomorphometric analysis revealed 23.14 ± 10.62% of lamellar bone, 19.43% ± 9.18% of woven bone, 23.35% ± 6.04% of osteoid, 17.16% ± 6.13% of biomaterial particles, and 16.93% ± 9.78% of medullary spaces. In the NBS group, histomorphometric analysis found 39.64% ± 12.02% of lamellar bone, 16.28% ± 7.75% of woven bone, 17.51% ± 4.87% of osteoid, 12.72% ± 5.36% of biomaterial particles, and 13.84% ± 6.53% of medullary spaces. Differences between groups for proportion of lamellar bone (P = .004) and osteoid (P = .0287) were statistically significant. Inflammatory infiltration was appreciated only in the NBS group. The enriched xenograft showed a statistically significant higher proportion of lamellar bone and osteoid; however, this was accompanied by an accentuated inflammatory infiltrate.