Evaluation of crystalline indexes obtained through infrared spectroscopy and x-ray diffraction in thermally treated human tooth samples

The crystalline indexes obtained through infrared spectroscopy (CI _IR ) and X-ray diffraction (CI _XRD ) were used to analyze the structural changes of dentin and enamel in human teeth when subjected to heat treatments between room temperature (25 °C) to 1200 °C in atmospheric air and argon. Thermogravimetric (TGA) and differential scanning calorimetry (DSC) analyses of sound powders were also used to support the analysis. As the temperature increased, the CI _XRD increased exhibiting a behavior like that of the crystal grain size, and the CI _IR increased until the β-TCP phase appeared. These results indicated that the CI _IR was more variable to structural changes than the CI _XRD .