The use of cone beam computed tomography to predetermine root canal lengths in molar teeth: a comparison between two-dimensional and three-dimensional measurements.

OBJECTIVES

The aim of this study was to evaluate the accuracy of two-dimensional (2D) and three-dimensional (3D) root canal length measurements in molar teeth using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

Root canal lengths of twenty molar teeth were measured with two different CBCT approaches. After adjusting the CBCT images, 2D measurements were performed within the sagittal plane between the apical foramen and the coronal reference (cusp). The 3D approach measured centrically in axial planes. A linear mixed model with random intercepts was fitted to compare differences between methods (2D and 3D). The correlation between CBCT measurements and the actual root canal length was evaluated using the Pearson correlation coefficient.

RESULTS

Differences between 3D measurements and the actual root canal lengths were significantly smaller compared to the 2D approach (p < 0.001). Mean differences were 0.32 and 0.58 mm, respectively. A high correlation was found between the actual root canal length and 3D measurements (Pearson correlation coefficient = 0.97). Compared to the actual root canal length, 80 % of the 3D measurements were within the limits of ±0.5 mm.

CONCLUSIONS

3D measurements of root canals in molar teeth are more accurate than simple 2D measurements and show a high correlation to the actual lengths.

CLINICAL RELEVANCE

In cases where a CBCT is already available, root canal lengths in molar teeth can be accurately predetermined using a standardized 3D approach.