Figure 2The gray level information of the 3rd step of the Al wedge was sampled with three nonoverlapping (25 �� 25 pixel) ROIs Carfilzomib cost using the Photoshop histogram tool. The data were statistically analysed using the repeated measures analysis of variance (ANOVA) technique (P < 0.001). Significance level was set at 5%.3. ResultsThe MGVs of the plates ranged between 125.22 and 254.82 for Group A and 129.38 and 197.12 for Group B. The MGVs of the plates for Groups A and B according to delay in scanning time are presented in Tables Tables11 and and2,2, respectively. Multivariate ANOVA revealed interactions between the MGVs of images among times, brands, cases, and steps (Table 3). There were statistically significant differences between the two PSPs (P < 0.001).
Repeated measures of ANOVA revealed that the MGVs of each step of the Al wedge were significantly different from each other for all scan delays (P < 0.001). Figures Figures33 and and44 depict the tendency for MGVs to increase or decrease according to the delay in scanning time. MGVs increased with increasing scanning delay, except in the group with original D��rr plate cases (Group A1), which showed stable MGV levels with no significant effect of either scanning delay or light source. Reduction in image quality began 5min after exposure for the other D��rr plate groups (Groups A2 and A3). The subgroups B1, B2, and B3 showed the same tendency when delay in scanning times and type of cases were considered, in contrast to the A subgroups.
MGVs from the Digora plates scanned 10min after exposure were not significantly different from those scanned immediately; however, longer delays showed significant differences in MGVs.Figure 3The MGVs of the three subgroups of the D��rr Dental plates according to delay in scanning time. Figure 4The MGVs of the three subgroups of the Digora Optime plates according to delay in scanning time. Table 1The MGVs of the plates for Group A according to delay in scanning time. Table 2The MGVs of the plates for Group B according to delay in scanning time. Table 3Multivariate test results based on four factor repeated measures ANOVA for changes in MGVs. 4. DiscussionDigital radiography is one of the fastest developing modern dental diagnostic techniques. Serious studies have been conducted to evaluate the diagnostic quality and clinical performance of these systems, PSP being one of the current favourites [1�C7, Carfilzomib 9, 10, 13�C24]. Several investigations have been made into PSP image quality [2, 8, 17, 19, 25], most of them comparisons among PSPs, other digital systems, and conventional radiographic film [3, 11, 26].