Purpose: Following tooth extraction, wound healing is characterized by remodeling and resorption of the alveolar bone at the extraction site. This produces reduction in ridge volume. Medical-grade calcium sulfate hemihydrate (MGCSH) has been proposed as a graft material for extraction sockets to minimize the reduction in ridge volume. The aim of this study was to investigate the influence of MGCSH on the histopathologic pattern of intrasocket regenerated bone and to evaluate histologically the healed MGCSH-grafted extraction socket site at 3 months postextraction. Materials and Methods: MGCSH was grafted in a fresh human extraction socket, and at 3 months a cylindric tissue specimen, 2.5 mm in diameter, was trephined from the previously grafted site and an implant was placed. Non-decalcified specimens were sectioned at a horizontal plane and stained for histologic and histomorphometric evaluation. Results: The mean trabecular area was 58.6% ± 9.2% in the coronal sections, 58.1% ± 6.2% in the middle sections, and 58.3% ± 7.8% in the apical sections. The differences in mean trabecular area between sections were not statistically significant. Discussion: It is significant that the MGCSH underwent complete resorption and replacement by newly formed bone because the most important negative attribute of other graft materials is the resorption time. Moreover, calcium sulfate shows great potential for guided bone regeneration in surgical sites. Conclusion: MGCSH seems to be an acceptable graft material for extraction socket bone regeneration because it is completely resorbable and allows new trabecular bone arrangement in a limited 3-month period.
Int J Oral Maxillofac Implants 2005;20:636–641

Key words: bone regeneration, calcium sulfate, tooth extraction, wound healing