ObjectiveTo evaluate the use of a synthetic bone substitute covered with a collagen membrane for ridge preservation after tooth extraction, by clinical and tomographic analysis. Material and MethodsFifteen patients, presenting at least two maxillary anterior teeth indicated for extraction, were selected: in the test group (TG), post-extraction sockets were filled by a synthetic bone substitute; in the control group (CG), by blood clot. In both groups, the sockets were covered by a collagen membrane. Cone-beam computerized tomography (CBCT) scans were acquired immediately after and 6months post-surgically, and horizontal and vertical dimensional bone changes were quantified. ResultsTransurgical clinical analysis presented no statistically significant differences between TG and CG (p>.05). CBCT intragroup evaluation presented statistically significant reduction for the buccal alveolar measurement (TG=1.58mm or 21.82%, and CG=1.66mm or 24.08%) and horizontal cervical measurement (TG=0.55mm or 8.30% and CG=1.30mm or 17.68%), and not significant for palatal alveolar measurement (TG=0.44mm or 3.42% and CG=0.26mm or 3.89%). For alveolar height and horizontal apical measurements, this decrease was significant only for the CG, with reductions of 1.03mm and 0.50mm, respectively, compared to a decrease of 0.57mm and 0.19mm for the TG. The intergroup analysis showed significant difference for cervical horizontal measurement after 6months (p<.05). ConclusionThe results showed that the use of the bone substitute covered with a collagen membrane resulted in less changes in vertical and horizontal alveolar ridge dimensions than the collagen membrane alone.