Comparison of four electronic root canal length measurement devices

How Do Different Image Modules Impact the Accuracy of Working Length Measurements in Digital Periapical Radiography? An In Vitro Study

Background/Objectives: This study aims to evaluate the accuracy of digital dental radiography in determining working length in root canal treatment via various image modules. Methods: A total of 40 intact single-rooted, single-canal human premolar teeth were examined. Following meticulous cleaning, the teeth were placed in a maxillary premolar socket within a dry human skull. X-ray images were systematically captured via a Carestream RVG digital sensor under standardized conditions. The digital images are processed under five distinct image modules: 1. original module, 2. autoenhancement module, 3. autoenhancement+negative module, 4. negative module, 5. colored module. Three calibrated observers determined the working length of each digital radiograph after the specified image modules were applied. The agreement between the actual working length and the lengths determined by the observers was evaluated via Pearson correlation analysis. A significance level of 0.05 was set for the statistical tests. Results: A high level of intra- and interobserver agreement, with a strong correlation between the actual measurements and all image module groups, was obtained (p < 0.001). The original image module group demonstrated the highest compatibility (ICC = 0.940, r = 0.912), whereas the colored image module group exhibited the lowest compatibility (ICC = 0.924, r = 0.879) with the actual measurement. Conclusions: This study demonstrates the accuracy of digital radiography in determining working length through the application of various image modules, with the original image module exhibiting the closest alignment to actual working lengths. These findings support the continued use and further development of computer-based image processing tools to optimize clinical outcomes in root canal therapy.

Accuracy of different electronic apex locators in determination of minimum Root perforation diameter

This study aims to evaluate the ability of Raypex 6, Propex Pixi, Dentaport ZX, Apex ID, Propex II and Dr.'s Finder NEO to detect minimum root canal perforation diameter. One hundred single-rooted, extracted human teeth were artificially perforated by 5 burs in different diameters (0.25-1.25 mm) in 5 mm above the apex. Twenty teeth were assigned to each group. The actual canal lengths (AL) were measured under stereomicroscope followed by a measurement of electronic canal length (EL) using each electronic apex locator (EAL). None of the EALs were able to detect the perforation at diameters of 0.50 and 0.25 mm. Although all EALs used in our study were unable to detect perforations at diameters of 0.5 mm and 0.25 mm, they were highly successful in the determination of simulated root perforations at diameters of 1.25, 1 and 0.75 mm.

The influence of periapical lesions on the repeatability of two electronic apex locators in vivo

OBJECTIVES

To determine the influence of periapical lesions on the repeatability of two electronic apex locators (EALs), Root ZX II, and RomiApex A-15, in maxillary anterior teeth, in vivo.

MATERIALS AND METHODS

After approval by the local ethics committee, 43 maxillary anterior teeth scheduled for root canal therapy were assigned to two groups. The periapical lesion (PAL) group included 21 teeth with necrotic pulps and radiographically visible periapical lesion, and the normal periapex (NPA) group consisted of 22 teeth with vital pulps and no periapical lesion. In each canal, Root ZX II and RomiApex A-15 were used to determine working length defined as the "zero" reading on the display. Two consecutive measurements were performed with each EAL on each tooth and a second operator measured the endodontic file with a digital caliper without knowledge of the EAL being used or the tooth diagnosis. The absolute value of the difference between the first and second measurement (measurement pairs) was calculated. Repeatability was evaluated by the Bland-Altman method, and an aligned ranks transformation ANOVA was conducted to compare the EALs.

RESULTS

The median absolute difference between measurement pairs was significantly lower (p < 0.001) and the limits of agreement were narrower in the NPA group. Among the EALs, median absolute differences were significantly smaller for Root ZX (p < 0.001).

CONCLUSIONS

Measurements were more repeatable when no periapical lesion was present. Root ZX showed better repeatability than RomiApex.

CLINICAL RELEVANCE

Periapical lesions seem to influence successive in vivo measurements with EALs.