Ridge preservation with the use of Bio-Oss collagen: A 6-month study in the dog

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.

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.

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.

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.

The placement of a biomaterial in an extraction socket may modify modeling and counteract marginal ridge contraction that occurs following tooth removal.