The aim of this study was to determine the change in working length (∆WL) before and after coronal flaring and after complete rotary instrumentation as a function of canal curvature. One mesiobuccal or mesiolingual canal from each of 43 extracted molars had coronal standardization and access performed. Once the access was completed, canal preparation was accomplished using Gates Glidden drills for coronal flaring and EndoSequence files for rotary instrumentation. WLs were obtained at 3 time points: pre-instrumentation (unflared), mid-instrumentation (flared) and post-instrumentation (concluded). Measurements were made via direct visualization (DV) and the CanalPro apex locator (EM) in triplicate by a single operator with blinding across the time points. Root curvature was measured using Schneider’s technique. The change in working length was assessed using repeated-measures ANCOVA. The direct visualization measurements were statistically larger than the electronic measurements (paired t-test difference = 0.20 mm, SE = 0.037, P < .0001), although a difference this large may not be clinically important. Overall, a greater change in working length was observed in straight canals than in curved canals. This unexpected finding was attributed to the limitations of the study, specifically the confounding factor of root length. This trend was more pronounced when measured electronically than via direct visualization, especially after complete instrumentation than after coronal flaring. The overall change in working length after complete instrumentation was found to be clinically insignificant in this study. A limited amount of change in working length may be expected prior to obturation.

Aim: The aim of this study was to evaluate the accuracy of the Wirele-X (Forum Tec, Ashkelon, Israel), a new Bluetooth-enabled electronic apex locator (EAL). The accuracy of the Wirele-X and the Root ZX II (J. Morita, Tokyo, Japan) was compared in vitro using an alginate model. Materials/Methods: Thirty-one extracted single-rooted human teeth with mature apices were decoronated at the CEJ. Under 10X magnification, actual canal lengths (ACL) were determined. The teeth were embedded in alginate and electronic canal length measurements were obtained using the Root ZX II and Wirele-X EALs. Each tooth was measured three times with both EALs. A blinded examiner measured each file with a digital micrometer to the nearest 0.01 mm. Differences between ACLs and the average measurements from the EALs were compared with Student's t test for related samples. Results: The average distance from the file tip to the apical foramen (AF) was -0.11 mm (±0.16) and -0.07 mm (±0.21) for the Root ZX II and Wirele-X systems, respectively. There were no statistically significant differences between the two apex locators in their ability to locate the AF (p > 0.05). Conclusions: Both the Wirele-X and the Root ZX II provided a high level of accuracy and reliability in locating the AF.

The aims of this study were to determine the efficacy of the KontrolFlexTM AccufileTM compared to the READY•STEEL™ Flexofile® using an electronic apex locator and to evaluate the instrument’s design via scanning electron microscopy. Actual canal lengths of thirty extracted teeth were determined under magnification. An alginate model was used to determine experimental canal lengths with the Root ZX II apex locator and size #10 Accufiles and Flexofiles. Differences between actual lengths and experimental lengths were compared with Student’s t test. The average experimental lengths were short of the actual length by -0.10 mm (±0.34) and -0.12 mm (±0.16) for the Accufile and Flexofile, respectively with no statistical difference (p > 0.05). SEM images revealed similar non-cutting “batt” tips and a square cross-section for the Accufile and triangular for the Flexofile. Both files provided similarly high levels of reliability when used with the Root ZX II electronic apex locator.

Title: Appropriateness of choice to walk or run, depending on the speed of a quick relocation with load carriage Objectives: Comparison of physiological response of organism during the walk and run at speed 6 - 7,4 km.h-1 with carried load 15 kg with follow-up determination of critical speed in connection with economy of these activities where there were discovered sizes of correlation with proportional representation of fat free mass and working length of lower limb. Methods: The method applied in this research was the quantitative research based on intra-individual and inter-individual comparative analysis. Results: Based on the measured data it has been found out that there is a critical speed at 7,43 km.h-1 (±0,53), with respect to economy of walk compared to run with 15 kg load. The average heart rate during the critical speed was 129 BPM (±9,67). The average energy expenditure per minute during the critical speed was 11,9 kcal (±2,04). In addition there were discovered sizes of correlation between critical speed and the working length of lower limb where rP = 0,9203 was statiscitally significant. (α = 0,05) and between critical speed and proportional representation of fat free mass, where rP = 0,1529 was not found to be statistically significant (α = 0,05). Keywords: quick relocation, load...

Indiana University-Purdue University Indianapolis (IUPUI) / Accurate determination of working length during endodontic therapy is a crucial step in achieving a predictable outcome. This is determined by the use of electronic apex locators, tactile perception, and knowledge of average tooth lengths and/or dental radiography whether digital or conventional is utilized. It is the aim of this study to determine if there is a difference between Schick digital radiography and Kodak Insight conventional film in accurately determining working lengths when modifying exposure time and source-film/sensor distance. Twelve teeth with size 15 K-flex files at varying known lengths from the anatomical apex were mounted in a resin-plaster mix to simulate bone density. Each tooth was radiographed while varying the source-film/sensor distance and exposure 122 time. Four dental professionals examined the images and films independently. Ten images and 10 films were selected at random and re-examined to determine each examiner?s repeatability. The error in working length was calculated as the observed value minus the known working length for each tooth type. A mixed-effects, full-factorial analysis of variance (ANOVA) model was used to model the error in working length. Included in the ANOVA model were fixed effects for type of image, distance, exposure time, and all two-way and three-way interactions. The repeatability of each examiner for each film type was assessed by estimating the intra-class correlation coefficient (ICC). The repeatability of each examiner on digital film was good with ICCs ranging from 0.67 to 1.0. Repeatability on the conventional film was poor with ICCs varying from -0.29 to 0.55.We found there was an overall difference between the conventional and digital films (p < 0.001). After adjusting for the effects of distance and exposure time, the error in the working length from the digital image was 0.1 mm shorter (95% CI: 0.06, 0.14) than the error in the working length from the film image. There was no difference among distances (p = 0.999) nor exposure time (p = 0.158) for film or images. Based on the results of our study we conclude that although there is a statistically significant difference, there is no clinically significant difference between digital radiography and conventional film when exposure time and source-film/sensor distance are adjusted.

Indiana University-Purdue University Indianapolis (IUPUI) / Accurate determination of working length during endodontic therapy is critical in achieving a predictable and successful outcome. Working length is determined by the use of electronic apex locators, tactile perception, knowledge of average tooth lengths and dental radiography. Due to the increasing use of digital radiography in clinical practice, a comparison with conventional film in working length determination is justified. The purpose of this study is to determine if there is a difference between Schick digital radiography and Kodak Ultra-speed film in the accurate determination of working lengths when vertical angulation of the object is variable. Twelve teeth with #15 K-flex files at varying known lengths from the anatomical apex were mounted in a resin-plaster mix to simulate bone density. A mounting jig for the standardization of projection geometries allowed for exact changes in vertical angulation as it related to the object (tooth) and the film/sensor. Each tooth was imaged using Schick CDR and Kodak Ultra-speed film at varying angles with a consistent source-film distance and exposure time. Four dental professionals examined the images and films independently and measured the distance from the tip of the file to radiographic apex and recorded their results. The error in working length was calculated as the observed value minus the known working length for each tooth type. A mixed-effects, full-factorial analysis of variance (ANOVA) model was used to model the error in working length. Included in the ANOVA model were fixed effects for type of image, vertical angulation, and the interaction of angle and film type. Tooth type and examiner were included in the model as random effects assuming a compound symmetry covariance structure. The repeatability of each examiner, for each film type, was assessed by estimating the intra-class correlation coefficient (ICC). The ICC was determined when 12 randomly selected images and radiographs were reevaluated 10 days after initial measurements. The repeatability of each examiner for Schick CDR was good with ICCs ranging from 0.67 to 1.0. Repeatability for the conventional film was poor with ICCs varying from -0.29 to 0.55. We found the error in the working length was not significantly different between film types (p = 0.402). After adjusting for angle, we found that error in the working length from the digital image was only 0.02 mm greater (95-percent CI: -0.03, 0.06) than the conventional film. Furthermore, there was not a significant difference among the angles (p = 0.246) nor in the interaction of image type with angle (p = 0.149). Based on the results of our study, we conclude that there is not a statistically significant difference in determining working length between Schick CDR and Kodak Ektaspeed film when vertical angulation is modified.