Effect of blood contamination on the push-out bond strength of two endodontic biomaterials

Abstract

Objectives: The aim of the present study was to compare the effect of blood contamination on the push-out bond strength of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) at different time intervals. Materials and Methods: One hundred and twenty dentin slices from single-rooted human teeth were sectioned and instrumented to achieve a diameter of 1.3 mm. The specimens were allocated into eight groups based on the materials used, the presence or absence of blood contamination, and the time. MTA and CEM were mixed and introduced into the lumens of dentin slices in groups 1–4 and 5–8, respectively. In blood-contaminated groups (1, 3, 5, and 7), the specimens were in direct contact with blood. The push-out test was performed in groups 1, 2, 5, and 6 after 3 days and in othergroups after 21 days. For the evaluation of failure modes, the samples were examined under a light microscope at × 40 magnifications. Data were analyzed by three-way analysis of variance (ANOVA). Results: The bond strength of MTA was higher than that of CEM, regardless of contamination and time (P < 0.05). For both materials, regardless of contamination, there was an increase in the bond strength from days 3to 21 (P < 0.05). Regardless of materials and time, blood contamination had no significant effect on the bond strength of materials (P > 0.05). Inspection of the samples revealed that the bond failure was predominantly of the mixed type in all groups. Conclusion: Blood contamination had no adverse effect on the bond strengths of both MTA and CEM; resistance of MTA to displacement was greater than that of CEM cement. However, the elapsed time, from 3 to 21 days, resulted in an increase in bond strength of both materials.