Effects of methods of hydration of a biphasic ceramic graft on bone regeneration of extraction socket defects.

Background: Alveolar volumetric changes are inherent to the healing process after tooth extraction and filling of the extraction site with biomaterials can reduce these volumetric changes and provide a more favorable environment for the future prosthetic restoration with implants. Among the biomaterials available, biphasic ceramic compounds have shown promissing clinical results, however, histologic evaluation of bone tissue response to different hydration and incorporation methods are limited. The objective of this study was to comparatively evaluate in vivo the osteoconductive potential of the biphasic ceramic bone substitute (SBC) composed of beta-tricalcium phosphate and hydroxyapatite after different hydration methodologies in rat extraction sockets.

Methods: Wistar rats (n = 20) were randomly distributed in two subgroups (G1, G2) according to the hydration methods used. After extraction of the right upper central incisor the alveoli were filled with SBC hydrated by two different methods. Group 1: biomaterial hydrated in blood; Group 2: biomaterial hydrated in physiologic saline. The animals were euthanized after 1 and 6 weeks for removal of the bone blocks containing the biomaterial and were submitted to histologic processing. Five-μm-thick demineralized sections of the samples were stained with hematoxylin and eosin (HE) and subjected to histomorphometric analysis.

Results: Bone formation was limited 7 days after the extraction procedure and increased in both groups between 7 and 42 days from surgery, demonstrating a time dependent increase of bone volume throughtout the experimental period (p < 0.05).

Conclusions: The hydration of SBC with saline significantly increased new bone formation and reduced connective tissue volume after 42 days demonstrating that hydration method may significantly influence bone healing in such defects, and, thus should be carefully performed.