Fractures in Root-Filled Premolars with Posts: Cone Beam CT Accuracy

Objective: To assess diagnostic accuracy for detecting vertical root fractures in root-filled teeth with fiber-resin and titanium posts using cone beam CT (CBCT). Methods: CBCT scans were acquired of 59 root-filled extracted human premolars provided with fiber-resin (n=30) or titanium (n=29) posts before and after the induction of non-displaced vertical root fractures using the Scanora 3D™ and i-CAT™ CBCT systems. Six oral-maxillofacial radiologists assessed the CBCT axial, sagittal and coronal sections interactively for the presence/absence of root fracture using OnDemand 3D™ software. Interobserver agreement was analyzed using Kappa (κ) statistics. Sensitivity, specificity and overall accuracy as well as positive and negative predictive values were calculated. The diagnostic accuracy variables were compared between the CBCT systems and post types using multivariate ANOVA and subsequently student-Newman-Keuls multiple-comparison test (α=0.05). Results: Interobserver agreement for fiber-resin posts ranged from 0.50-0.70 (Scanora 3D™) and 0.35-0.76 (i-CAT™) whereas for titanium posts, the κ coefficients varied from 0.42-0.80 (Scanora 3D™) and 0.31-0.73 (i-CAT™). Post type had a significant effect on sensitivity and negative predictive value. Statistically significant higher sensitivity (0.85±0.04; P=0.0128) and negative predictive value (0.88±0.03; P=0.0006) were observed using the i-CAT™ system in roots with fiber-resin posts than with the other combinations. Conclusion: The diagnostic accuracy for detecting vertical root fractures using CBCT was higher for roots with fiber-resin compared to titanium posts.