Figure 6.

(a) TGA plot of weight loss of dental tissues: pure organic tooth with the inorganic content removed (black line), dentine (red line) and enamel (blue line). (b) A schematic of the ultrastructural alteration of organic matrix and HAp crystallites in human dentine upon heating. The process begins with the superior thermal expansion of the organic matrix compared with the HAp crystallites, resulting in compression of HAp during heating (red arrow). The compression relaxes gradually as the organic matrix begins to denature and burn off, leading to the additional expansion in the HAp crystallites in excess of the pure thermal strain. (Online version in colour.)