Evaluate the width and height dimension in dental human sockets covered by an impermeable barrier for a guided bone regeneration technique. Sixteen tooth extractions were performed, divided into two groups: a) Study group (n = 10), with polypropylene barrier; b) Control group (n = 6), without polypropylene barrier. The alveoli of both groups were filled with only blood coat. The evaluation was clinical to measure width, and radiographic for height. Evaluations were done immediately after tooth extraction and four months later. The mean reduction in width was lower in the study group (p < 0.05, bi-flow test), while in height there was no difference between groups (p > 0.05, bi-flow test). The width loss was lower in the barrier group, but there was no difference between groups in height loss.