The diabetic dental pulp repair – involvement of vascular endothelial growth factor and bone morphogenetic protein 2

Abstract

Introduction/Objective We aimed to investigate the effects of diabetes mellitus (DM) on rat dental pulp repair by measuring time-dependent changes in expressions of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP 2) following direct pulp capping.

Methods Two groups, each of 20 Wistar rats, received either streptozotocin (for DM induction) or the same volume of sterile saline. A week later, the pulp of maxillary and mandibular right incisors in diabetic and non-diabetic groups were exposed and capped with calcium hydroxide in order to provoke reparative response. The levels of VEGF and BMP 2 were determined in the pulp tissue lysates one and seven days after the pulp capping, using enzyme-linked immunosorbent assays.

Results Diabetic state per se increased VEGF level, with a peak at first day after the pulp capping (19.3 ± 0.9 pg/mg, p < 0.001), but did not affect BMP 2 levels. Significant increase of BMP 2 expression was noticed on the seventh day in capped pulp, but only in diabetic rats (16.7 ± 1 pg/mg, p = 0.001). Positive correlation between VEGF and BMP 2 was found on the seventh day following capping, only in diabetic pulp (r = 0.905, p = 0.003).

Conclusion Diabetes-induced increase in VEGF expression reflects changes in the inflammatory phase of pulp repair in DM. Increase in BMP 2 expression suggest that stimulating effect of calcium hydroxide appears seven days after diabetic pulp capping.

Keywords: dental pulp capping; diabetes; vascular endothelial growth factor; bone morphogenetic protein 2; calcium hydroxide