Influence of blood and moisture on mineral trioxide aggregate at varying depths during retrograde application: An in vitro study – Part 1

Abstract

This in vitro study evaluated the influence of blood contamination on the surface hardness of mineral trioxide aggregate (MTA) when used as a retrograde filling material. Forty-two extracted single-rooted teeth were prepared, obturated, and resected apically by 3 mm. Root-end cavities were filled with MTA, and the specimens were divided into two groups based on the immersion medium: distilled water and whole blood without anticoagulants. After 24 h of immersion, the samples were sectioned at 0 mm, 1 mm, and 2 mm from the apex, and surface hardness was measured using a Shore D hardness tester. Statistical analysis using one-way ANOVA and Bonferroni post hoc test revealed no significant difference in hardness between the two media ( P > 0.05). However, hardness values decreased significantly with increasing distance from the apex ( P < 0.005). It was concluded that blood does not adversely affect MTA hardness, whereas insufficient moisture hampers complete setting at deeper levels.