Atividade da mieloperoxidase e metaloproteinase 8 da matriz em resposta a diferentes materiais capeadores para pulpotomias em ratos Wistar

Abstract

The initial reactions of capping materials on pulp tissue are not well understood. The matrix metalloproteinases-8 (MMP8) acts on remodeling the extracellular matrix and myeloperoxidase (MPO) is associated to neutrophil infiltration in the tissues. This study aimed to evaluate the pulp tissue of rats’ molars after pulpotomies with mineral trioxide aggregate (MTA), BiodentineTM (BDT) and calcium hydroxide (CH) associated with sterile saline solution, at 24 and 72 hours, 7 and 15 days through correlating MPO activity with active neutrophils and MMP8 (EC3.4.24.34) activity with tissue remodelation. Thirty six Wistar rats were randomly distributed into groups: control, MTA, BDT and CH and subdivided according to the study period of de 24 and 72 hours, 7 and 15 days after pulpotomy and one was used for the control. MMP8 activity was evaluated through fluorescence technique and MPO activity was determined using the MPO assay. A gradual decrease of MPO and MM8 activity occurred in group MTA over the experimental periods (p<.05). Unlikely, groups BDT and CH exhibited an increase in the activity at 7 and 15 days (p<.05). MTA demonstrated a decrease in MPO and MMP8 values indicating a potentially curative activity in pulp tissue. Conversely, BDT and CH showed the increasing of the irritating potential which makes difficult the healing process.