Does ambient light exposure of photostimulable phosphor plates compromise the radiographic diagnosis of simulated internal root resorption?

Abstract

Objectives: To evaluate the impact of ambient exposure of photostimulable phosphor (PSP) plates and digital enhancement on detecting internal root resorption (IRR).

Methods: Thirty-five single-rooted teeth were selected, including 15 with artificially induced IRR (via 3-hour immersion in 37% hydrochloric acid) and 20 controls. Three repeated periapical radiographs were acquired of each tooth using the parallelling technique and PSP plates from the Express, VistaScan Mini, and CS 7600 digital radiographic imaging systems. For each set of 3 X-ray exposures, prior to scanning, one PSP plate was kept shielded from ambient light, another was exposed to ambient light for 5 seconds, while the third was exposed for 10 seconds. The presence of IRR in the total sample of 315 radiographs was assessed by 4 independent examiners using a 5-point scale. Initially, digital enhancement was not allowed, and these images were considered originals. A second round was conducted with adjustments permitted (enhanced radiographs). Sensitivity, specificity, and area under the receiver operating characteristic curve were calculated and compared using 2-way analysis of variance (α = 0.05).

Results: No significant differences were found among different light exposure times across all systems (P > .05). In the CS 7600, enhanced radiographs showed significantly higher sensitivity and lower specificity compared to originals (P < .05).

Conclusions: Ambient light exposure of PSP for up to 10 seconds does not compromise IRR diagnosis. Digital enhancement in CS 7600 may increase detection but reduce specificity, requiring cautious interpretation to avoid overdiagnosis.