Purpose: Reduction of alveolar height and width after tooth extraction may present problems for implant placement, since bone volume is important for biologic and esthetic reasons. The aim of this study was to assess bone healing of large bone defects grafted with collagen sheets and maintenance of reactive soft tissue, evaluating cone beam computed tomography (CBCT) scans and histomorphometric results. Materials and Methods: Patients presented large bone defects after tooth extractions. Reactive soft tissue was left in the defects filled by collagen sheets. Vertical bone volume was assessed by CBCT examinations before tooth extractions and 3 months later. At 3 months, cylinder bone samples were obtained for histology and histomorphometry analysis. Results: Twenty-six patients were included in the clinical study. Examined defects reported mean bone gain of 12.13 ± 3.91 mm, and mean vertical bone levels showed a statistically significant increase (P .05) at 3 months after extraction. Histologic examinations revealed bone formation; mean vital bone measurements were 41.59% ± 5.80%, and connective tissue percentages averaged 50.37% ± 7.73%. Conclusion: Reactive soft tissue left in large bone defects after tooth extraction and grafted collagen may support a significant vertical bone gain and vital bone formation. Keywords: bone defects, collagen, cone beam computed tomography, reactive soft tissue