Influence of ambient light viewing conditions on imaging diagnosis of simulated internal root resorption in different devices.

The objective of this in vitro study was to analyze the influence of ambient lighting on the detection of simulated internal root resorption in images viewed on different digital devices. A total of 26 extracted single-rooted human teeth were sectioned longitudinally, and each half was coated with red enamel, leaving a 2-mm-diameter area exposed on the internal root surface. After the halves were rejoined with utility wax, the teeth were divided into 2 groups (n = 13) and submerged in 37% hydrochloric acid for different periods to create type 1 (2 hours) and type 2 (3 hours) resorption defects. Digital periapical radiographs were acquired before sectioning, after sectioning, and after simulation of resorption and then assessed by 3 experienced radiologists on 3 types of digital devices (27-inch desktop computer, 9.7-inch tablet computer, and 6.1-inch smartphone) under 2 lighting conditions (well-lit [427- to 461-lux] and darkened [0.0- to 15.5-lux]). Each image set was judged for the presence or absence of resorption using a 5-point scale. Sensitivity, specificity, and area under the receiver operating characteristic curve (Az) values for the diagnoses were analyzed through 1-way analysis of variance (significance level of 5%). Overall, the tests yielded high sensitivity, specificity, and Az values for all devices and lighting conditions. For simulated type 2 lesions, the sensitivity and specificity values were similar for well-lit and dark environments, except for the tablet device, which showed slightly reduced sensitivity and specificity without illumination, and the smartphone, whose specificity also had a lower value in this condition. These differences were not statistically significant. There was no statistically significant difference between different devices and lighting conditions regardless of the size of the resorption (type 1, P = 0.495; type 2, P = 0.520). Under the conditions of this study, ambient lighting and different devices did not influence the diagnosis of internal root resorption, allowing for flexibility in diagnostic conditions.