Fresnel-propagated submicrometer x-ray imaging of water-immersed tooth dentin

Structural investigations of materials in diverse fields such as biomimetics, materials engineering, and medicine have much to benefit from 3D nondestructive microscopy of representative samples of wet tissues. Phase contrast appearing in tomograms produced by Fresnel propagation of partially coherent x-ray fields is useful for visualizing submicrometer features within water-immersed samples. However, spurious contributions such as those due to randomly appearing bubbles lead to distorted images. By improving the statistics during image acquisition and reconstruction, submicrometer-sized tubules in human tooth dentin are observed. This type of wet imaging is directly applicable to the study of many mineralized tissues.