title: Effect of blood contamination on the retention characteristics of two endodontic biomaterials in simulated furcation perforations.
abstract: BACKGROUND
  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.
authors.affiliation: Dental and Periodontal Research Center, Department of Endodontics, Dental Faculty, Tabriz University (Medical Sciences), Tabriz, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Rahimi
authors.forename: Negin
authors.initials: N
authors.lastname: Ghasemi
authors.forename: Shahriar
authors.initials: S
authors.lastname: Shahi
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Lotfi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Froughreyhani
authors.forename: Amin Salem
authors.initials: AS
authors.lastname: Milani
authors.forename: Mahmood
authors.initials: M
authors.lastname: Bahari
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D001769:Blood; D017610:Calcium Compounds / Q000737:chemistry; D001840:Dental Bonding; D003786:Dental Pulp Cavity / Q000293:injuries / Q000648:ultrastructure; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000293:injuries / Q000648:ultrastructure; D004338:Drug Combinations; D006801:Humans; D008963:Molar / Q000293:injuries; D010087:Oxides / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D018915:Root Canal Preparation / Q000009:adverse effects*; D017640:Silicates / Q000737:chemistry; D013314:Stress, Mechanical; D013997:Time Factors; D014092:Tooth Root / Q000293:injuries* / Q000648:ultrastructure
chemical_list: D017607:Aluminum Compounds; D001672:Biocompatible Materials; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate