INTRODUCTION: The aim of the present study was to compare the effect of blood contamination on retention characteristics of white mineral trioxide aggregate (WMTA) and calcium-enriched mixture (CEM) in reconstructions of the furcation area. METHODS: Furcal perforations, measuring 1.3 mm in diameter and 2 mm in height, were produced in 180 human mandibular first molars. The teeth were divided into 12 groups of 15. WMTA and CEM were used in groups 1-6 and 7-12, respectively, for perforation repair. In groups 1, 3, 5, 7, 9, and 11 the walls of the perforated area were contaminated with blood; normal saline was injected in the remaining groups. Push-out test was carried out in groups 1, 2, 7, and 8 after 24 hours, in groups 3, 4, 9, and 10 after 72 hours, and in the remaining groups 7 days after placement of the materials by using a Universal test machine. To evaluate the failure modes, the samples were sectioned at furcation floor area, divided in two in the vertical direction, and evaluated under a stereomicroscope at × 40 magnification. Data were analyzed with multivariate analysis of variance and post hoc Tukey tests. RESULTS: The highest (6.75 MPa) and lowest (1.77 MPa) bond strength values were recorded in groups CEM/no blood contamination at 7 days and MTA/blood contamination at 24 hours, respectively. There were no statistically significant differences in bond strength between MTA and CEM (P < .05). However, there were significant differences in bond strength between blood-contaminated and uncontaminated groups in both materials (P < .05); time had exerted a significant effect on the bond strength of the study groups (P < .05). Failure patterns were of the mixed type in all the samples. CONCLUSIONS: Resistance of both WMTA and CEM to displacement was similar, and elapse of time from 24 hours to 7 days and contamination resulted in an increase and decrease in bond strength of these 2 materials to dentin, respectively.
INTRODUCTION: The aim of the present study was to compare the effect of blood contamination on retention characteristics of white mineral trioxide aggregate (WMTA) and calcium-enriched mixture (CEM) in reconstructions of the furcation area. METHODS: Furcal perforations, measuring 1.3 mm in diameter and 2 mm in height, were produced in 180 human mandibular first molars. The teeth were divided into 12 groups of 15. WMTA and CEM were used in groups 1-6 and 7-12, respectively, for perforation repair. In groups 1, 3, 5, 7, 9, and 11 the walls of the perforated area were contaminated with blood; normal saline was injected in the remaining groups. Push-out test was carried out in groups 1, 2, 7, and 8 after 24 hours, in groups 3, 4, 9, and 10 after 72 hours, and in the remaining groups 7 days after placement of the materials by using a Universal test machine. To evaluate the failure modes, the samples were sectioned at furcation floor area, divided in two in the vertical direction, and evaluated under a stereomicroscope at × 40 magnification. Data were analyzed with multivariate analysis of variance and post hoc Tukey tests. RESULTS: The highest (6.75 MPa) and lowest (1.77 MPa) bond strength values were recorded in groups CEM/no blood contamination at 7 days and MTA/blood contamination at 24 hours, respectively. There were no statistically significant differences in bond strength between MTA and CEM (P < .05). However, there were significant differences in bond strength between blood-contaminated and uncontaminated groups in both materials (P < .05); time had exerted a significant effect on the bond strength of the study groups (P < .05). Failure patterns were of the mixed type in all the samples. CONCLUSIONS: Resistance of both WMTA and CEM to displacement was similar, and elapse of time from 24 hours to 7 days and contamination resulted in an increase and decrease in bond strength of these 2 materials to dentin, respectively.