Mapping the Enamel Crystallite Orientation Distribution at the Mesoscale

Gaps in our understanding of the microscopic architecture of dental enamel are a major obstacle to progress in rational prophylaxis and minimally invasive intervention in dentistry. It is thought that the enamel crystallite orientation distribution (COD) impacts mechanical properties, diffusive transport, and the kinetics of dissolution. The current textbook model of human enamel posits systematic differences in the COD between rod and interrod (IR) enamel, and even within rods, but recent data challenges some of the assertions. An equivalent model for murine enamel, the most important pre-clinical model, does not yet exist. Diffraction/texture tomography (at ID13 EH3) may uniquely be able to report on the COD with a resolution that is sufficient to resolve rod and IR enamel (250 nm voxels) and a field of view that spans multiple rods (5-10 µm period). To establish feasibility, we propose to compare the COD in three major enamel types and perform correlative XRD and XRF tomography.