Background: In previous short-term studies, it was observed that while the placement of biomaterial in alveolar sockets may promote bone formation and ridge preservation, the graft may in fact also delay healing.
Aim: The objective of the present experiment was to evaluate the more long-term effect on hard tissue formation and the amount of ridge augmentation that can occur by the placement of a xenogeneic graft in extraction sockets of dogs.
Material and methods: Five beagle dogs were used. The third mandibular premolars were hemi-sected. The distal roots were carefully removed. A graft consisting of Bio-Oss collagen was placed in one socket while the contra-lateral site was left without grafting. After 6 months of healing, the dogs were euthanized and biopsies were sampled. From each experimental site, four ground sections - two from the mesial root and two from the healed socket - were prepared, stained and examined under a microscope.
Results: The placement of Bio-Oss collagen in the fresh extraction socket served as a scaffold for tissue modeling but did not enhance new bone formation. In comparison with the non-grafted sites, the dimension of the alveolar process as well as the profile of the ridge was better preserved in Bio-Oss-grafted sites.
Conclusion: The placement of a biomaterial in an extraction socket may modify modeling and counteract marginal ridge contraction that occurs following tooth removal.