Intramembraneous bone tissue responses to calcium sulfate: an experimental study in the rabbit maxilla

The purpose of this study was to histologically examine the responses of intramembraneous bone to calcium sulfate (CaS) and evaluate the resorption and replacement process.

Fourteen rabbits were used in this study. Defect healing without any filling material was compared with CaS. Five millimetres wide and 4 mm deep defects were drilled with a trephine bur on both sides of the edentulous space between the incisors and the molars. Test vs. control sites were randomly selected and thereby compared in each animal. The animals were killed after 2, 4 and 8 weeks for histological examination.

After 2 weeks, the specimens showed a great extent of degradation of CaS. No signs of the material could be seen after 4 and 8 weeks. There were no statistically significant differences in bone regeneration between the test and control sites within the 8 weeks group in this study. However, there was tendency of more blood vessels in the test sites after 4 weeks of healing.

The present study showed that CaS does not interfere with intramembraneous bone healing. In this animal model, the CaS exhibited resorption/degradation early in the healing process while seemingly stimulating angiogenesis. However, there was no significant increase in bone regeneration in the sites treated with CaS during an 8 week period of healing and observation time, as compared with a control defect.