Comparative Assessment of Crystalline Structure of Powder and Bulk Human Dental Enamel Using X-Ray Diffraction Analysis

Abstract Objectives The aim of the present study was to assess and compare the crystalline structure of powder and bulk human dental enamel using X-Ray Diffraction Analysis. Methods The buccal surfaces of 60 selected non-carious third molars were divided into two groups including powdered and bulk enamel specimens. For preparation of enamel powders, the enamel tissues were ground and powdered manually using a mortar and pestle. For bulk samples, the enamel slabs were sectioned using a low-speed diamond saw. The crystalline structure of samples was analysed using an X-ray diffraction equipment and the obtained data were analysed. The values of the lattice parameters were obtained using the equation of hexagonal crystalline structures. The crystal size and the microstrain of crystallites were calculated using both Scherrer's and Williamson-hall methods. The total area under the peaks were considered as the criteria for assessment of crystallinity. The data was analysed by parametric independent t-test and nonparametric Mann–Whitney test using SPSS for windows at a significance level of 0.05. Results The results of current study revealed significant difference between the crystallinity value and crystal size of two study groups (p ≤ 0.001). The powder samples showed higher crystallinity and smaller crystal size than bulk samples. The obtained strain values of powder samples were almost twice as high as the bulk samples, this difference was not statistically significant. Conclusions Based on the results of the current study, the sample preparation method of human tooth enamel can affect the crystalline data obtained from X-ray diffraction analysis.