The effect of zinc oxide based sealer on bone defects healing

Summary Introduction Obturation as the final phase of endodontic treatment aims to provide complete hermetic filling along the entire length of the canal system from the coronal opening to the apical end. The aim of this study was to evaluate histological response of bone tissue on the implantaton of zinc oxide based material in artificially prepared defect in the mandible of rats. Material and method For the experiment, sixteen male Wistar rats were used. Using sterile steel burs a defect was made in mandible, between the midline and mental foramen. Zinc oxide based sealer was implanted in the defects of experimental group while the defects of control group healed spontaneously. One half of animals in both groups were sacrificed after thirty days, and the second half after ninety days. Microscopic preparations consisted of the defect with surrounding bone and after processing were analysed using light microscopy. Results The thirtieth day after implantation of the material, fibrovascular connective tissue was noted, with scant chronic inflammatory cell infiltrate. Away from the experimentally made defect, in the depth of the bone, lamellar bone with well-formed larger osteons was noted as well as enlarged Volkmann and Haversian canals. Ninety days after implantation of the material, there was no restitutio ad integrum, but intense focal remodelling of bone tissue was noted. Conclusion Endomethasone N slowed down bone tissue healing process by showing the signs of prolonged inflammation in bone tissue in which it has been implanted. Extension of the healing process is reflected in the slow replacement of fibrovascular connective tissue with newly formed bone tissue.