An in vitro comparison of dentin removal using Liberator and K-FlexoFile

Numerous studies have shown that NiTi rotary instruments can effectively produce a well-tapered root canal form, with minimal risk of transportation. This study aimed to compare of dentin removal from mesiolingual canal walls of human extracted mandibular first molars using liberator and K-FlexoFile. In this experimental study, the initial images of 40 mesial roots of extracted mandibular first molars were scanned at 2, 4.5 and 7 mm from the apex by CT Scan system. Samples were divided in two groups. F group was prepared with K-FlexoFile and L group was prepared with Liberator files. Post-instrumentation images was recorded. The amount of dentin removal and canal transportations were evaluated and analyzed by ANOVA and t-test. At the coronal level of F-group, the most removal was done from distobuccal wall (0/17 0/07mm)and it had significant difference with the least removal from mesial wall (0/10 0/07mm)(p<0.005).L group had the most removal from distal wall(0.18 0.07mm) and the difference from mesial(0.09 0.04mm)and lingual walls was significant(p<0.05).At The middle level, F group did the most removal from lingual wall which had significant difference with mesial and distobuccal walls(p<0.05). But there was no significant difference between dentin removal in L group at this level.At the apical level, in both of the groups, the most removal was done from lingual and mesial walls with no significant difference between them(p>0.05). At the coronal level,there was no significant difference between two groups in dentin removal and both of them especially Liberator,attacked danger zones.. At the middle and apical levels,both of the groups well did the most removal from the lingual thick wall.