Computer simulations of X-ray phase-contrast images and microtomographic observation of tubules in dentin

J Synchrotron Radiat. 2020 Mar 1;27(Pt 2):462-467. doi: 10.1107/S1600577519016503. Epub 2020 Jan 27.

Abstract

An investigation of the problems of X-ray imaging of dentinal tubules is presented. Two main points are addressed. In the first part of this paper, the problem of computer simulating tubule images recorded in a coherent synchrotron radiation (SR) beam has been discussed. A phantom material which involved a two-dimensional lattice of the tubules with parameters similar to those of dentin was considered. By a comparative examination of two approximations, it was found that the method of phase-contrast imaging is valid if the number of tubules along the beam is less than 100. Calculated images from a lattice of 50 × 50 tubules are periodic in free space but depend strongly on the distance between the specimen and the detector. In the second part, SR microtomographic experiments with millimetre-sized dentin samples in a partially coherent beam have been described. Tomograms were reconstructed from experimental projections using a technique for incoherent radiation. The main result of this part is the three-dimensional rendering of the directions of the tubules in a volume of the samples. Generation of the directions is possible because a tomogram shows the positions of the tubules. However, a detailed tubule cross-section structure cannot be restored.

Keywords: computer simulations; dentinal tubules; phase-contrast imaging; phase-contrast tomography.

MeSH terms

  • Computer Simulation
  • Dentin / ultrastructure*
  • Humans
  • Microscopy, Phase-Contrast
  • Photons
  • Synchrotrons*
  • X-Ray Microtomography
  • X-Rays