Clinical and histologic evaluation of the demineralized freeze-dried bone membrane used for ridge augmentation

The biologic principle of guided bone regeneration has been successfully used to regenerate alveolar ridges. The objective of this pilot study was to clinically and histologically evaluate the demineralized freeze-dried bone membrane. Four premolar teeth were extracted from two dogs, and the remaining alveolar bone was surgically reduced in width and height to produce Class III ridge defects. After a 2-month healing period, mucoperiosteal flaps were elevated, and demineralized freeze-dried cortical columns were used as space maintainers. Bone membranes were used as barriers. The animals were sacrificed at 3 months and the surgical areas were recovered and processed for histologic evaluation. Results showed ridge augmentation in all sites. Clinically, the augmented areas appeared to have the same hardness as the surrounding bone on the periphery of the experimental site. After elevation of a mucoperiosteal flap, the bone membrane could be seen. Histologically, the bone membrane acted as an efficient barrier, excluding the nonosteogenic tissues. New bone formation underneath the membrane was found in all specimens. This study suggests that a bone membrane in combination with a space maintainer can guide new bone formation to regenerate localized chronic alveolar ridge defects.