The effect of dental bleaching on pulpal tissue response in a diabetic animal model: a study of immunoregulatory cytokines

摘要

Abstract Aim To evaluate the influence of tooth bleaching on immunoregulatory cytokines production ( IL ‐6, Tumour necrosis factor ( TNF )‐α and IL ‐17) in the pulp tissue of normoglycaemic and diabetic rats. Methodology Twenty‐eight rats were divided into normoglycaemic and diabetic rats ( n ?=?14). Diabetes mellitus ( DM ) was induced with a single dose of alloxan diluted in citrate buffer via intramuscular injection. After DM confirmation, all rats were sedated and tooth bleaching was performed using 35% hydrogen peroxide on the right maxillary molars for 30?min. Left molars were used as controls. Bleaching resulted in four hemimaxillae groups: normoglycaemic (N), N‐bleached ( NB le), diabetic (D) and D‐bleached ( DB le). After 2 and 30?days, rats were euthanized and hemimaxillae processed for analysis by haematoxylin and eosin and immunohistochemistry. Results within and between animals were submitted to Wilcoxon signed‐rank and Mann–Whitney tests ( P? ? 0.05). Results At 2?days, the NB le group had mild, and the DB le had severe inflammatory infiltration in the pulpal tissue ( P? ? 0.05). TNF ‐α and IL ‐6 cytokines were associated with increased immunolabelling in the bleached groups compared to nonbleached ( P? ? 0.05). However, IL ‐17 had increased immunolabelling in the NB le compared to the N and DB le group ( P? ? 0.05). At 30?days, reactionary dentine was observed in the coronal pulp of all bleached teeth and no inflammation was present ( P? ? 0.05). TNF ‐α cytokines had increased immunolabelling in the DB le group compared to the D group ( P? ? 0.05). However, for IL ‐6 and IL ‐17, no difference was observed in this period ( P? ? 0.05). Conclusions Tooth bleaching increased IL ‐6 and TNF ‐α in the pulp tissue regardless of diabetes mellitus; however, diabetic rats had higher TNF ‐α levels for longer periods. Tooth bleaching influenced the increase in IL ‐17 in the early periods in normoglycaemic rats.