Apical microleakage in root canal-treated teeth containing broken hand files obturated with two different obturating materials: An in vitro study

Introduction: Separated instruments in root canals complicate routine endodontic treatment. This study aimed to compare apical microleakage in root canals containing separated hand stainless steel K-files obturated with gutta-percha and Portland cement. Materials and Methods: In this in vitro, experimental study, forty single-rooted freshly extracted teeth were decoronated and then the roots were randomly divided into four groups (n = 40). The biomechanical preparation was done according to the step-back technique. The K-file of 25 size was intentionally broken in apical third and obturation was done with gutta-percha and AH Plus sealer using lateral compaction technique and with Portland cement. Apical microleakage was measured using dye penetration method; teeth were immersed in Indian ink for 48 h. The roots were rinsed and sectioned by a cutting saw. The sections were evaluated under a stereomicroscope under ×50 magnification by two observers. Data were analyzed using ANOVA test. Results: Root canals filled with Portland cement have shown lowest microleakage when compared to laterally compacted gutta-percha according to dye penetration depth. Statistical results with ANOVA have showed a significant difference in microleakage among the four groups (P < 0.001, significant). Conclusion: The results of this study have shown that apical microleakage is less in instrument-separated teeth obturated with Portland cement than in instrument-separated teeth obturated with gutta-percha.