Background:The initial electronic apex locator (EAL) length measurement is generally established with a small-sized file. It is not known whether file size would be interfering with the reading accuracy of the EAL. This study aimed to evaluate the effect of file size on the accuracy of Root ZX apex locator using an agar model when sodium hypochlorite solution or blood was present during electronic measurements in enlarged root canals. Methods: A total of 36 extracted lower premolars were used. In stage 1, the canals were instrumented using size 10-40 K-files with a size 40 K-file as the master apical file (MAF). The teeth were then divided randomly into two groups of 18 teeth each. In group A, the teeth were mounted in one per cent agar and irrigated with six per cent sodium hypochlorite solution (NaOCl), while in group B the teeth were mounted in agar and irrigated with human blood. In stage 2, the canals were enlarged using a size 60 K-file as the MAF. In stages 1 and 2, the apical portions of the canals were instrumented using the step-back sequence (up to a size 80 K-file). In stage 3, the canals were enlarged using a size 80 K-file as the MAF. In each stage, the length was measured with a Root ZX until the meter value reached 'APEX' using small and large size files. Results: Three-way ANOVA and Bonferroni test showed that file size, stage of preparation and type of irrigant all had a significant influence on the measurement error (P<0.0001), with all the interactions between these three factors being significant (P<0.0001). Conclusions:As the diameter of the root canal increased, the measured length with the smaller size files became shorter. A file of a size close to the prepared canal diameter should be used for root length measurement in the presence of blood. In the presence of NaOCl, the Root ZX was highly accurate even when the file was much smaller than the diameter of the canal. The agar model was effective and suitable for testing EALs in vitro.Key words: Agar, blood, electronic apex locator, file size, root length determination, root canal preparation, sodium hypochlorite.Abbreviations and acronyms: EAL = electronic apex locator; MAF = master apical file; NaOCl = sodium hypochlorite solution.

Background:The aim of this ex vivo study was to evaluate the accuracy of four electronic apex locators (EALs) to determine the working length in teeth with various foramen diameters. Our previous study revealed that electronically measured canal length was influenced by the root canal diameter. It is not known whether foramen size would interfere with the reading accuracy of an EAL. Methods: A total of 36 extracted human lower single rooted premolar teeth were divided into four groups of nine teeth each. In groups A, B and C, the root canals were instrumented using #10-80, #10-100 and #10-120 K-files, and the tip of size #80, #100 and #120 K-files were permitted to pass through the apical foramen to a length of 1mm, respectively. In group D, the teeth were instrumented using #10-140 K-files and the tip of #140 K-file was permitted to pass through the apical foramen to a length of 5mm. Thus, the average apical foramen diameters in groups A, B, C and D were approximately 0.82mm, 1.02mm, 1.22mm and 1.5mm, respectively. The teeth were then mounted in 1% agar and four EALs were used: Root ZX, Foramatron D10, Apex NRG and Apit 7. For electronic measurement, sizes #10 and #80, #10 and #100, #10 and #120, and #10 and #140 K-files were used for groups A, B, C and D, respectively. During electronic measurement the canals were flushed with 6% sodium hypochlorite solution. Results: Three-way ANOVA and Bonferroni test showed that EAL, file size and foramen size all had a significant influence on the measurement error (P<0.0001), with all the interactions between these three factors being significant (P<0.0001). Conclusions:The four EALs were unreliable to determine the working length of teeth with a wide apical foramen, when using a small size file. The Root ZX and Foramatron D10 showed significantly better scores than the other two EALs and may be more reliable to determine the working length of teeth with a wide apical foramen, if a tight-fit file is used.Key words: Agar, apical foramen, electronic apex locators, root length determination, root canal preparation.Abbreviations and acronyms: ANOVA = analysis of variance; CDJ = cementodentinal junction; EAL = electronic apex locator; NaOCI = sodium hypochlorite solution.

Background: The aim of this study was to examine the effects of root canal irrigants on the accuracy of Dentaport ZX TM® electronic apex locator (EAL) in enlarged root canals. Our previous study revealed that as the diameter of the root canal increased, the electronically measured length with small size files became shorter in the presence of blood. It is not known whether different canal irrigants would interfere with the reading accuracy of an EAL in enlarged root canals. Methods: A total of 45 extracted single-rooted human teeth were used. In Stage 1, canals were instrumented using #10-40 K-files with a #40 K-file as the master apical file (MAF). The teeth were randomly divided into five groups and mounted in an experimental apparatus. The following irrigants were used during electronic canal measurements: Group A = 0.5% NaOCl; Group B = 2.5% NaOCl; Group C = 15% EDTA; Group D = 0.8% chlorhexidine (CHX); and Group E = RC Prep. In Stage 2, the canals were enlarged using a #60 K-file as the MAF. In Stages 1 and 2, the apical portion of the canals was instrumented using the step-back sequence (up to a #80 K-file). In Stage 3, the canals were enlarged again using a #80 K-file as the MAF. In each stage, the canal length was measured with a Dentaport ZX TM® using #10 and #40, #10 and #60, and #10 and #80 K-files for Stages 1, 2 and 3, respectively. Data were analysed by two-way ANOVA and Fisher's PLSD test. Results: Statistical analysis showed significant differences among all groups (p<0.01). There was no significant difference between Group A and B at each stage and between Group D and E at Stage 2. A statistical significant difference was observed between #10 K-file and other files (#40, #60 and #80) at each stage (p<0.01). In Groups A and B, there was no significant difference between #10 and S C I E N T I F I C A RT I C L E#40 K-files (Stage 1) and between #10 and #60 Kfiles (Stage 2). Conclusion: The Dentaport ZX TM® was accurate and not adversely affected by the presence of 0.5% or 2.5% NaOCl and EDTA in the enlarged canals, and the measured lengths obtained with small and large size files were comparable. However, it was accurate in the presence of CHX and RC Prep only when large size files were used, and the length measured with small size files was greater than the actual length.Key words: Electronic apex locator, file size, irrigants, root length determination, root canal preparation.Abbreviations and acronyms: ANOVA = analysis of variance; CHX = chlorhexidine; EDTA = ethylenediamine tetraacetic acid; Fisher's PLSD test = Fisher's Protected Least Significant Difference test; MAF = master apical file; NaOCl = sodium hypochlorite solution.

The purpose of this study was to compare the clinical outcomes of BPTB ACL reconstruction using the AMP or the TT technique for the femoral tunnel drilling. A Medline search was not ableto recognize any examination legitimately contrasting the clinical results of the AMP and the TT methods. The writing search distinguished test examines distributed from 1966 to March 2009 where in any event one gathering went through arthroscopic autologous BPTB ACLreconstructions utilizing either the AMP or the TT procedure for the femoral passage drilling.Twenty-one examinations, including a sum of 859 patients (257in the AMP and 602 in the TT gathering), were remembered for this investigation. The AMP bunch exhibited altogether before re-visitation of run and fundamentally more prominent scope of movement, Lachman test esteems, and KT-1000 arthrometer estimations. The utilization of the AMP evoked more noteworthy knee dependability and scope of movement esteems, and prior re-visitation of run contrasted with the TT technique.These results may show a likely advantage of the AMP over the TT strategy. Notwithstanding, as the advantages of the AMP were not gotten in the mid and long haul subsequent meet-ups, generally there is no authoritative proof now to infer that one procedure is better than the other. Randomized controlled preliminaries legitimately contrasting the utilization of the two procedures and long haul subsequent meet -ups will help explain which one, ifany, gives best clinical results.