Human teeth has “structure” and yet is mostly treated as material. Differentiation between material and structure is crucial to understand complex biological material such as human dentine. The aim of the present work is to determine the bioceramic gradient phases of the crystal structure of the teeth across the crown and root region with age. Around 50 samples of teeth of different age groups were collected, decontaminated and sintered at 400, 600 and 800°C. After removal of the enamel the root and crown regions were machined and characterized for their vibrational states by FTIR investigations. The studies indicate the presence of hydroxyapatite as the major phase after sintering along with the typical hydroxyl peaks. A weight loss ranging from 7 - 42 % after sintering at 400 and 800°C respectively was observed across the different age groups. A through analysis would provide us an understanding in studying the desired nature of the teeth and kinetics of tooth mineralization.