A Clinical Approach Using Scheduled-For-Extraction Teeth to Validate a Classic In Vitro Method to Assess the...

This study aimed to validate a commonly used in vitro methodology of testing the performance of the EALs. For that, clinical data obtained from teeth already scheduled for extraction were used to compare the accuracy and precision of an EAL in determining the position of the apical foramen in both clinical and laboratory settings using micro-CT imaging.

In a clinical setting, the working length of 11 canals was established using the Root ZX II apex locator. Subsequently, these teeth were extracted and imaged with and without the file in place using micro-CT technology. In vitro measurements of the working length were then obtained in these same teeth using an alginate model and new micro-CT scans were performed. Datasets were co-registered and the accuracy and precision of both in vivo and in vitro models were compared by measuring the distance from the file tip to a tangential line crossing the foramen margins, with a tolerance level of ±0.5 mm. Statistical comparisons were performed using Friedman post hoc Related Samples Sign and Bland-Altman tests with a significance level set at 5%.

Statistical analysis revealed no significant difference between the accuracy (p = 0.368) and precision (p = 0.761) measurements obtained in both in vivo and in vitro conditions. Additionally, the Bland-Altman analysis revealed an agreement between in vivo and in vitro methods (p > 0.05).

The in vitro methodology using freshly mixed alginate demonstrated consistent accuracy and precision in identifying the position of the apical foramen, when compared to in vivo measurements.