Accuracy of linear and volumetric measurements of artificial ERR cavities by using CBCT images obtained at 4 different voxel sizes and measured by using 4 different software: an ex vivo research.

OBJECTIVES: To compare the accuracy of linear and volumetric measurements of artificial external root resorption (ERR) cavities by cone beam CT (CBCT) images obtained at four voxel sizes and by using four different software ex vivo.

METHODS: ERR cavities were created on 40 extracted single rooted anterior teeth. Images were obtained by using Planmeca CBCT unit at endo mode (0.075 mm); high-resolution mode (0.1 mm); high-definition mode (0.15 mm) and normal resolution mode (0.2 mm) voxel sizes. Images were analyzed by two observers using four different software (Romexis, 3D Doctor, ITK-SNAP, and OsiriX). (1) Diameter; (2) height; (3) depth; and (4) volume of the ERR were measured. CBCT measurements were then compared with direct physical measurements. ANOVA was used with general linear model analysis. The significance level was set at p < 0.05.

RESULTS: One-way ANOVA general linear model analysis showed no significant difference between or within observers for diameter, height, depth and volume measurements (p > 0.05). We found significant differences for diameter and volume measurements among softwares in terms of mean differences as compared to mean standard direct measurements (p < 0.05). We found statistically significant differences among voxel sizes and software for height measurements (p < 0.05). In addition, we found significant differences for diameter and volume measurements (p < 0.05) suggesting more accurate measurements for the cervical region when compared to apical region.

CONCLUSIONS: Observers using CBCT images obtained at four voxel sizes performed similarly in the quantification of artificial ERR with clinically insignificant distinction between CBCT softwares used.