Ultrasound examination with color power Doppler to assess the early response of apical periodontitis to the endodontic treatment

The purpose of this study was to assess the possibility to detect early vascular changes in apical periodontitis (AP) using ultrasound examination with color power Doppler (US-CPD) and to establish a correlation between the early response of AP to treatment and its potential healing. Twenty-one apical lesions were visualized with US-CPD before endodontic treatment, 1 week after the first access to endodontic system and 4 weeks after root canal obturation. A differential diagnosis between cystic lesions (CLs) and granulomatous lesions (GLs) was attempted. The vascular modifications were then correlated with long-term radiographic follow-up using Fisher's exact test. The decrease or disappearance of vascular flow observed in AP 4 weeks after root canal obturation was significantly related to a healing trend (p = 0.0206) of the lesions. Combining the data with preoperative US-CPD diagnosis showed a reproducibility for GLs only (p = 0.0022). This study showed the possibility to detect early vascular changes in AP using US-CPD, correlating them with a healing trend after endodontic treatment. Future investigations should be conducted and more attention should be dedicated to the potential of this alternative and biologically safe imaging technique. US-CPD in endodontics may be a helpful tool to identify healing processes after endodontic treatment and to understand the behavior of different forms of AP.