Impact of room lighting and image display device in the radiographic appearances of the endodontic treatments.

Objectives: To assess the radiographic appearances of the endodontic treatment in different room lighting conditions and image display devices.

Methods: After approval by Research Ethical Board, 20 images were obtained from blocks with one endodontically treated tooth. Of the 20 endodontic treatments conducted in the laboratory, of those the randomly selected 10 teeth (50% of sample) received some quality defect in three parameters-apical limit, adaptation to root canal and homogeneity of the root canal filling material. Digital radiographs (DIGORA® Optime, Soredex, Milwaukee, WI) were obtained, which were evaluated (8 times) by 10 observers in two different conditions of room lighting, with bright (1000 to 1200 lux) and dim light (25 to 50 lux), using two different image display devices, smartphones and laptop computers. The observers assessed the radiographic appearances of the endodontic treatment with respect to quality of each one of three parameters individually. The data of observers' responses in terms of the quality of each parameter were statistically compared using Cronbach's α coefficient, diagnostic tests, π coefficient and ANOVA with Tukey tests, at a significant level setting of 5% (α = 0.05).

Results: The mean of reliability of observer responses ranged from 0.89 (intra-evaluator) to 0.66 (inter-evaluator). The mean values of the receiver operating characteristic (ROC) area were 0.661 (PD = 0.098), with laptop in bright lighting appraising homogeneity of the root canal filling material on the worst performance (ROC area = 0.57), which was statistically significant (p < 0.05), and 0.81 with laptop in dim lighting appraising apical limit on the best performance. Differences (p < 0.05) occurred mainly among parameters used for assessment.

Conclusions: Room lighting and image display devices have very little influence in the radiographic appearances of the endodontic treatment. Thus, we suggest the use of smartphones as an acceptable image display device in daily clinical practice in routine bright lighting conditions.