Potencial de biomineralização e biocompatibilidade de dois cimentos reparadores endodônticos - estudo em tecido subcutâneo de ratos

Abstract

Materials with biocompatibility and biomineralization capacity for the root canal system and periapical tissues are essential for a good outcome of endodontic treatment. The objective of the study was to compare the tissue reaction and the biomineralization potential of a calcium silicate cement: Biodentine (BD) and the White Mineral Trioxide Aggregate (MTA) in rat subcutaneous tissue. Thirty male Wistar rats were divided into four groups. The materials were implanted in the subcutaneous tissue of the back of these animals, inside polyethylene tubes. The groups consisted of the experimental periods corresponding to 15, 30 and 60 days after the surgical procedure, when they were euthanized. Tissues of 15, 30 and 60 days were taken to the histopathological analysis and, in order to quantify the inflammatory resp onse and to evaluate possible formation of mineralization structures through the Von Kossa test, times 30 and 60 days were used. Quantification of IL-1β and IL-8 cytokines by ELISA and qPCR for bone morphogenetic proteins (BMP-2 and BMP-4) and osteocalcin were performed at periods of 30 and 60 days. The sham group showed a slight variation in the profile and intensity of the inflammatory infiltrate. The control group had significantly higher inflammatory scores on day 15 than the Sham group. It was observed that BD showed similar inflammatory response to the sham group, without significant variation throughout the experimental periods. The MTA group presented a significant increase of a chronic inflammatory profile at day 30 with a significant reduction of t his to day 60 when compared to Sham. The granulation tissue in the Sham group showed no significant variation in all experimental periods. The control and BD groups were significantly higher on days 15 and 30 when compared to Sham with significant reduction on day 60 when compared to day 15. The MTA group did not show significant variation at all times. The groups did not present necrosis or endocytosed material. BD and MTA showed significant positive kossa areas. BD and MTA showed significant increase for IL-1β when compared to control group, and BD increased significantly for IL-8, in both periods. In qPCR, gene expression for BMP-2 was significant only for BD in both periods, BMP -4 and OC were significant only for MTA, in both periods. It is concluded that BD and MTA are biocompatible, stimulate mineralization, stimulating expression of osteogenic genes.