Evaluation of inflammatory response and biomineralization of different root canal dressing: study in subcutaneous tissue of rats

Abstract

Calcium hydroxide based materials are known for their high bioactivity, proving to be effective in mineralizing capacity and tissue response, in addition to their recognized antimicrobial capacity. In vitro ceramics have also shown excellent properties with potential for use as root canal dressing. The aim of this study is to evaluate the biocompatibility and mineralizing capacity of experimental pastes produced from new in vitro-ceramic formulations, F18, F18 + cobalt and to compare them with conventional calcium hydroxide paste. Four polyethylene tubes will be implanted randomly on the back of 16 Wistar rats, filled with one of the materials, or empty for control. After 7 and 30 days, euthanasia will be performed and the tubes will be removed with the surrounding tissue. The specimens will be processed for hematoxylin-eosin (H.E.), picrosirius red (PSR), von Kossa staining and, without staining, for observation in polarized light. Pre-established scores will be assigned to the inflammatory infiltrate and the fibrous capsule around the tube will be classified as thin or thick in HE staining. For analysis of PSR collagen fiber maturation, greenish yellow fibers considered immature and thin will be accounted and, the yellowish-red fibers, considered mature and thick; For biomineralization analysis, von Kossa positive and birefringent polarized light structures will be considered as present or absent. Data will be submitted to appropriate statistical tests after normality test (p <0.05).