Comparative in Vivo Assessment of Digital Radiograph Software and Apex Locator for Working Length Determination

Accurate determination of the working length (WL) is essential for the success of root canal treatment, ensuring proper cleaning, shaping, and obturation of the canal system while avoiding apical over-instrumentation or inadequate preparation. Usually, WL is determined using a combination of electrometric devices and periapical radiographs, yet the increasing availability of digital radiographic software offers new opportunities for more precise measurement. The aim of this study was to estimate the ability of the software Planmeca Romexis viewer (Planmeca Group, Helsinki, Finland) to measure WL on periapical digital radiographs, and to compare its performance with electrometric measurements obtained using an electronic apex locator. The WL was established under direct vision with a stereomicroscope. Periapical radiographs were taken under standardised conditions, and WL was measured digitally using the linear measurement tools of the Romexis software. Electrometric WL values were also recorded for each tooth. All values were statistically compared with the actual lengths to assess accuracy and consistency. The results demonstrated a strong correlation between electrometric measurements and the actual WL, with minimal deviations. The digital radiographic measurements using Planmeca Romexis also showed a high level of accuracy, though slightly less consistent than the electrometric method, particularly in cases with anatomical variations or radiographic superimposition. Within the limitations of this in vitro study, electrometric and digital radiographic measurements proved reliable for WL determination. The Planmeca Romexis software can serve as a valuable adjunct in clinical practice, complementing electrometric methods in endodontic treatment.