Cross-sectional analysis of detection of external root resorptions simulated by digital subtraction radiography: in vitro study

Early detection of external root resorption (ERR) is important for the adoption of an appropriate treatment plan in order to avoid greater damage in root structures. The present study aimed to evaluate the efficacy of digital subtraction radiography (DSR) for detecting root resorptions in maxillary central incisors. The ERRs were simulated and analyzed through digital radiographs and DSR methods.This study selected 36 maxillary central incisors with healthy roots. The teeth had their original root length reduced by 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm in the apical-coronal direction. Then, the teethwere regularly and irregularly worn with dental bur on the buccal surface, 4 mm cervical to the tooth’s apex, featuring two groups (n = 20 and n= 16, respectively). The digital radiographs were obtained using a photostimulable storage phosphor (PSP) imaging plate, and the images were subtracted by the linear and logarithmic methods. Ten dentists tested the diagnostic capacity of digital radiography and of digital subtraction radiography in detecting the ERRs. The DSR, both linear and logarithm, had a better performance when compared to the evaluation conducted only with digital radiography in apical and buccal ERRs of 0.5 mm and 1.0 mm (P< 0.05).The digital subtraction radiography method, both linear and logarithm,wasmore effective in the identification of small external root resorptions than digital radiography and can aid dental professionals in the early detection of ERRs.