The study aimed to compare and evaluate the accuracy of iPex, Root ZX mini, and Epex Pro Electronic apex locators (EALs) in diagnosing root perforations in both dry and in different wet conditions: 5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 17% Ethylenediaminetetraacetic acid (EDTA). Methods: Thirty extracted, human single rooted mandibular premolars were artificially perforated with a diameter of 1.5 mm in middle third of root. Actual canal lengths (ALs) in millimetre (mm) were evaluated for all teeth up to perforation location, and alginate mould were used to embed the teeth. After this, the electronic measurements were calculated by all EALs up to perforation site using a 20 K-file in both dry and wet canal conditions. Up to the perforation sites, the ALs were subtracted from the electronic length. Statistical analyses were done using One-way ANOVA with post hoc tukey's test for pairwise comparison and the level of significance was set at 0.05. Results: All three EAL's detected canal perforations which were clinically acceptable. There was significant difference for dry and wet conditions. Most accurate measurement were seen in dry canals for all three EALs. Root ZX mini in dry condition showed most accurate reading and there was a significant difference when compared with other groups. No significance difference was observed in iPex and Epex Pro Apex locator, and between NaOCl and CHX, CHX and EDTA. Conclusion: Perforations were determined within a clinical acceptable range of 0.03-0.05 mm by all three EALs. Root ZX mini in dry canals gave most accurate measurement. The presence of irrigating solution influenced the accuracy of all the apex locators.

Aim. The aim of the study was to compare the dentinal microcrack formation on human mandibular molars using 4 different minimally invasive file systems at 3, 6 and 9 mm from apex using a stereomicroscope. Method. 125 mesial roots of mandibular molars were randomly divided into 5 groups and instrumented (n=25). Group 1: Control Group (CG), Group 2: Self Adjusting File (SAF), Group 3: XP-Endoshaper (XP), Group 4: TRUShape (TS), Group 5: V Taper 2H (VT). After instrumentation was completed, the roots were sectioned at 3 mm, 6 mm, and 9 mm from apex using a slow-speed circular saw. Digital images were captured using a 24x stereomicroscope by using a digital camera. Two operators independently checked each specimen for the presence of dentinal defects. Statistical comparison between the file systems was done using Chi-square (p<0.05). Result. There was no statistically significant difference in the frequency of microcracks between the groups of file systems (X2=4.509, p>0.05). VT file system exhibited higher microcracks (25%) but was not statistically significantly higher than XP (12%), TRUShape (12%), and SAF (4%) endodontic file systems. Conclusion. Within the limitations of this study, it can be concluded that all the file systems used in our research are minimally invasive files and produced few dentinal microcracks. VT files produced maximum while SAF produced the least number of micro-cracks.