Application of a 3D segmentation software to micro-CT imaging of dental materials interfaces

In order to analyze the interfacial behavior of dental materials, micro-CT imaging has been widely applied in research, since it allows to obtain non-destructive images with high resolution. However, most of the papers analyze the obtained volumes through 2D-sectioning and linear manual measurements. This paper applied a 3D segmentation software to micro-CT dataset in order to achieve a comprehensive analysis of the interface and compare it with conventional measurements. Twenty teeth were prepared, crowned and scanned with micro-CT before and after artificial aging in order to evaluate the marginal gap presence and progression. Conventional linear analysis consisted in four manual linear measurements in sixteen marginal points. On the other hand, 3D segmentation was performed to automatically detect the volume representing discontinuity along the tooth-restoration complex. Results showed no correspondence between obtained results in terms trend when comparing volumetric and linear analyses. Linear measurements allowed a better characterization of the discrepancy in terms of vertical and horizontal extension. On contrary, 3D segmentation workflow was standardized, less time-consuming and it allowed to export the interfacial gap volume for further superimposition after aging. Severe yet localized interfacial failures were detected only by 3D evaluation. Further studies are necessary in order to better evaluate the accuracy of the procedure, which showed promising, results.