Evaluation of the bond strengths to dentine of root-end placed different endodontic repair materials in the presence / absence of blood contamination

Objective: The aim of this in vitro study is evaluation of bond strength to dentin of root end placed MTA Repair HP, RetroMTA and MTA Flow in the presence or absence of blood contamination. Materials and Methods: In this study, ninety single-rooted maxillary central teeth were used. After endodontic treatment was applied to the teeth, the root end were resected 3 mm and retrograd cavities were prepared. First, samples were divided into (+/-) 2 groups according to the contamination with blood of the cavities. Later, samples was divided into three subgroups (n=15) according to the root end filling materials (MTA Repair HP, RetroMTA, MTA Flow) and these materials were prepared and applied to the cavity according to the manufacturer's instructions. After the samples were kept at 37°C in 100% humid environment for 21 days, 1.0±0.1 mm slices were obtained from the root end of each tooth, and they were subjected to the push-out bond strength test with the universal test device. Each slice was examined under a stereomicroscope to evaluate the failure mode. The data were analyzed using one‑way analysis of variance and Independent Sample T Test. Results: Bond strength to dentin was significantly negatively affected by the presence of blood contamination (p <0.05). The highest average bond strength value was observed in the MTA Flow (-) group and the lowest average bond strenght value was observed in the MTA Repair HP (+) group. No significant difference was found between MTA Flow and RetroMTA while MTA Repair HP showed the lowest bond strength in both the blood contaminated group and the non-blood contaminated group. Conclusion: As a result, it has been found that blood contamination reduces the bond strength to dentin, MTA Flow shows the highest bond strength and MTA Repair HP shows the lowest bond strength among the materials.