RUNX‐2, OPN and OCN expression induced by grey and white mineral trioxide aggregate in normal and hypertensive rats

Aim To investigate whether hypertension affects white and grey mineral trioxide aggregate (MTA Angelus ®) mineralization implanted subcutaneously into rats by assaying osteoblastic biomarkers. Methodology Polyethylene tubes containing grey MTA Angelus ®, white MTA Angelus ®, intermediate restorative material (IRM; positive control), or an empty tube (negative control) were implanted into the dorsal connective tissue of spontaneous hypertensive (n = 12) and Wistar (normotensive; n = 10) rats. Half of the rats in each group were killed after 7 days, and the remaining after 30 days. Tubes with surrounding tissue were removed and immunostaining was performed to detect RUNX-2, OPN and OCN proteins. The normality of data was analysed by the Shapiro-Wilk test. Comparison of two independent groups was performed thru Mann-Whitney U test, to detect a significant difference. A post hoc test accounting for multiple comparisons was performed following Tukey's test (p <0.05). Results Under hypertensive conditions after 30 days, both MTA materials were associated with immunolabeling for RUNX-2 from low to moderate, which was less than that observed at normal blood pressure and the 7-day groups (p <0.05). OPN and OCN protein expression under both MTA conditions was considered low after both 7 and 30 days for the hypertensive condition, and was less than that in the normal blood-pressure animals after 30 days (p <0.05). No immunostaining for any biomarkers in the control and IRM groups was observed (p <0.05). Conclusion Hypertension decreased the immunostaining of RUNX-2, OPN, and OCN biomarkers in response to MTA. Thus, hypertension can jeopardise the mineralization ability of MTA and may have a negative impact on endodontic treatment outcomes. This article is protected by copyright. All rights reserved.