Can a high-density dental material affect the automatic exposure compensation of digital radiographic images?

To investigate the influence of high-density dental material on the automatic exposure compensation of digital radiographic imaging systems.

Two radiographic phantoms were custom made to reproduce radiographic densities of the dental tissues: enamel, dentin and pulp chamber. The phantoms were X-rayed using the Digora Toto, Digora Optime and VistaScan systems for 0.063, 0.1 and 0.16  s. Radiographic acquisitions were repeated in the presence of a high-density material equivalent to a titanium implant, in the small and large sizes. Mean grey values of the dental tissue-equivalent regions were obtained with the Image J software, averaged and compared between the absence and presence of the high-density material using ANOVA for multiple comparisons and Tukey's test (α = 0.05).

The presence of a high-density material significantly (p ≤ 0.05) decreased grey values of the dental tissue-equivalent images in the Digora Toto and VistaScan, regardless of the exposure time. For the Digora Optime, the high-density material decreased the pulp-equivalent grey values at all exposure times, the dentin-equivalent grey values significantly increased at exposure time of the 0.1 and 0.16  s, and the enamel-equivalent grey values significantly increased at the exposure time of 0.16  s (p ≤ 0.05). In general, the size of the high-density material did not affect the grey values significantly (p ≤ 0.05).

In general, the presence of a high-density dental material in digital radiographic systems influences the AEC by adjusting dental tissue-equivalent grey values.