Objectives: to investigate the biocompatibility and osteoinductivity of bioactive glass (BAG), mineral trioxide aggregate (MTA) and TheraCal™ LC on bone healing in surgically created defects in rat femurs through histological investigation and immunohistochemical detection of TNF-α as a pro-inflammatory mediator.
Methods: 45 mature rats were divided into 3 experimental groups included three bioactive materials (n=10), a negative control group (n=5) and a positive control group (n=10). The animals were then sacrificed 2 and 5 weeks postoperatively. Histologic evaluations comprising inflammation severity and new bone formation were made on H&E-stained decalcified sections.
Results: Histological results of the experimental groups revealed early processes of bone healing in 2 weeks period but they showed a highly osteoinductive effect at the end of 5 weeks period. The effects of MTA &TheraCal on bone formation both at 2- and 5-weeks period were higher than BAG. Immunohistochemical detection of TNF-α of 2 weeks specimens exhibited strong positive staining reaction of bone marrow tissue for the positive control and three experimental groups with no significant difference. In contrast, Negative to weak immunostaining reactivity of 5 weeks specimens was observed in the positive control and three experimental groups with no significant difference.
Conclusion: BAG, MTA and TheraCal™ LC bioactive materials are comparable to each other in their biocompatibility and showing bone formation with regression of the inflammatory activity and less fibrous tissue in the repaired region were seen 2 weeks and increased 5 weeks after their implantation.