This study evaluated the retention characteristics of ProRoot mineral trioxide aggregate (MTA), RetroMTA, Supra MTA, and Biodentine biomaterials used to repair furcation perforations contaminated with blood. Furcal perforations measuring 1.3 mm in diameter and 2 mm in height were created in 96 mandibular first molar teeth, which were then randomly divided into the following two groups (n = 48): contaminated (+) or non-contaminated (-) with blood. The groups were subdivided into four groups (n = 12) according to the material used (ProRoot MTA, RetroMTA, Supra MTA, and Biodentine) to seal the perforations. The samples were allowed to set for 14 days and were then subjected to push-out testing. The results were analyzed using ANOVA, and the failure modes were examined using a surgical microscope. ProRoot MTA (+/-) and RetroMTA (+/-) exhibited superior bond strength values; in addition, there were no significant differences among these groups (P > 0.05). Biodentine (+) showed intermediate values that were sometimes statistically similar to the ProRoot MTA (+/-) and RetroMTA (+/-) groups (P > 0.05) and, at other times, the Biodentine (-) and Supra MTA (+/-) groups (P > 0.05). The lowest bond strength values were shown by the Biodentine (-) and Supra MTA groups (P > 0.05). "Adhesive failure mode" was the most frequently observed type for all tested materials. Blood contamination did not affect the dislocation resistance of materials.