# Effect of the Blooming Artifact Reduction filter on the detection of voids in root canal fillings using cone-beam computed tomography images

## TL;DR

This study tested how a filter reduces imaging artifacts in root canal fillings, improving void detection in some cases using cone-beam CT.

## Contribution

The study demonstrates that the BAR filter's effectiveness depends on the CBCT device and sealer type used.

## Key findings

- The BAR filter improved ROC values for void detection in the apical third with AHPJ and BCS in OP300 scans.
- Specificity for detecting voids in the apical third with AHPJ increased significantly in OP300 scans using the BAR filter.
- In VeraView X800 scans, the BAR filter improved specificity for detecting voids in the cervical/middle thirds with BCS.

## Abstract

This study evaluated the effectiveness of the blooming artifact reduction (BAR) filter (e-Vol DX Software, CDT, Bauru, SP, Brazil) for detecting voids in root canals filled with various sealers, using two CBCT devices and micro-CT as a reference. Twenty mandibular incisors with long-oval root canals were filled with AH Plus Jet (AHPJ) or Bio-C Sealer (BCS). Each tooth was placed in the mandibular alveolar socket of a dry skull, covered with Mix-D material, and scanned with VeraView X800 and OP300 Maxio CBCT devices. Micro-CT images served as a reference. Three calibrated examiners assessed the CBCT scans, without and with the BAR filter (intensity level 1 for OP300 Maxio and level 3 for VeraView X800), for void detection using a 5-point scale. Diagnostic values (area under the receiver operating characteristic (ROC) curve, sensitivity, and specificity) were compared using multi-way analysis of variance (p=0.05). Intra- and inter-observer agreement was evaluated using the weighted Kappa index. For OP300, using BAR filter 1 significantly improved ROC curve values for detecting voids in the apical third with AHPJ and BCS (p<0.05). It also increased specificity for detecting voids in the apical third with AHPJ (p<0.05). For VeraView X800, the ROC curve and sensitivity values were unaffected (p>0.05), but using BAR filter 3 significantly enhanced specificity for detecting voids in the cervical/middle thirds with BCS (p<0.05). The diagnostic performance of the BAR filter is CBCT-device dependent. In OP300 scans, it enhances the detection of voids in the apical third with AHPJ and BCS. In VeraView X800 scans, it improves specificity for detecting voids in the cervical/middle thirds with BCS.