RESUMEN
OBJECTIVE: To evaluate dimensional alterations of the alveolar ridge that occurred following tooth extraction at sites grafted with Bio-Oss(®) Collagen. MATERIAL AND METHODS: Twenty-eight subjects with maxillary incisors, canines, and premolars scheduled for extraction were included. The tooth was carefully removed. The patients were randomly assigned to a test or a control group. In the test group patients, Bio-Oss(®) Collagen was placed in the fresh extraction socket while in the controls no grafting was performed. Radiographic examination (cone beam computed tomograms, CBCT) was performed immediately after tooth extraction and socket treatment. Four months later, a new CBCT was obtained. In the radiographs, (i) the distance (mm) between base of the alveolar process (apex) and the buccal and palatal crests was determined, (ii) the outer profile of alveolar process of the experimental sites was outlined, and the cross section of the area (mm(2) ) determined. RESULTS: After 4 months of healing, the buccal and to a less extent also the palatal bone plate had become markedly reduced in height. The placement of a biomaterial in the socket failed to prevent resorption of the buccal and palatal bone walls. The cross-sectional area of the control ridge was reduced about 25% and of the test ridge with 3%. CONCLUSION: The placement of a xenograft in fresh extraction sockets markedly counteracted the reduction in the hard tissue component of the edentulous sites.