Aim:This aim of this study was to evaluate the number of bacteria extruded apically during root canal preparation using Four Rotary instrumentation techniques.Materials and Methods:A total of 50 extracted mandibular premolars were selected, access cavities prepared and inserted in to rubber stoppers of 10 mL glass vial. Root canals were contaminated with a suspension of Enterococcus faecalis (E. faecalis) American Type Culture Collection (ATCC) 29212 and incubated for 24 h at 37°C. Debris extruded from the apical foramen during instrumentation was collected into vials. The numbers of Colony-forming units were determined for each sample.Statistical Analysis:The data obtained were analyzed using the one-way ANOVA followed by post-hoc tukey's test with a P = 0.05 as the level for statistical significance.Results:Results suggested a statistically significant difference in the number of colony forming units between four experimental rotary Nickel-Titanium instrumentation groups (P < 0.001).Conclusion:Although, extrusion of bacteria was found in all the experimental groups. There was less bacterial extrusion in K3 Group while more bacterial extrusion was seen in Mtwo Group.

This case report is on endodontic retreatment of a maxillary central incisor with two roots. A twenty-year-old male patient presented with pain in maxillary left central incisor. Radiographic examination showed an incompletely filled canal and an additional palatal root with periapical radiolucent lesion. Conventional cleaning and shaping of both the roots, i.e., buccal and additional palatal root canals was performed and obturation was done. After one year recall examination, the tooth was asymptomatic and periapical lesion had healed.