Hard tissue alterations after overaugmentation of the extraction socket

Objectives: The aim of the following experimental study was to assess bone changes in the horizontal and vertical dimension when the buccal aspect of the extraction socket was overaugmented at time of tooth extraction.

Material and Methods: Four extraction sites in the beagle dog were randomly assigned to one of the following treatments: Tx1: Augmentation of the buccal bone plate with BioOss Collagen® and BioGuide® Tx2: The buccal bone plate was forced into the buccal direction with a specially designed instrument Tx3: The buccal soft tissue was augmented with a modified soft tissue graft Tx 4: No treatment of the buccal bone plate. In each experimental site socket-preservation was conducted with BioOss Collagen® and a free gingival graft. After four months histologic analysis was conducted. The vertical and horizontal dimension of the extraction socket was evaluated.

Results: The mean vertical height of the buccal bone plate was -3.2 ± 0.2 mm for Tx1; -2.8 ± 0.2 mm for Tx2, -3.1 ± 0.3 mm for Tx3 and -2.7 ± 0.3 mm for Tx4. The horizontal dimension of the alveolar process was 4.8 ± 0.3 mm for Tx1, 4.9 ± 0.2 mm for Tx2, 3.7 ± 0.3 mm for Tx3 and 3.6 ± 0.3 for Tx4.

When the results from the horizontal dimension were tested with the analysis of variance (ANOVA), a clear significance could be found between the test groups Tx1 and Tx2 and the Tx3 and Tx4 groups (p<0.001).

Conclusion: Incorporation of BioOss Collagen® into the extraction socket and overaugmentation of the buccal bone plate seems to have no influence on the resorption process of the buccal bone plate. Yet overaugmentation of the buccal bone plate seems be able to compensate for the resorption process of the buccal bone plate to a certain extend.