MULTISCALE MODELLING OF ENAMEL DEMINERALISATION AND ACELLULAR REPAIR

Dental erosion is defined as the loss of dental hard tissues through chemical dissolution of the tooth structure without bacterial involvement [1]. Erosion is classically defined as having an intrinsic aetiology (due to exposure of tooth surfaces to gastro-intestinal acids) or extrinsic aetiology [2] (due to exposure of the teeth to dietary/environmental acids). Dental erosion has an increasing prevalence in the developed world and represents a significant challenge to dental practitioners in terms of the predictable management of the damaged dentition. As a progressive condition (due to the lack of intrinsic biological repair mechanisms for dental enamel), dental erosion is of relevance to our ageing population. Prevention therefore remains key, and whilst behavioural change (diet or amelioration of intrinsic factors) is essential, consumer products to delay, prevent and reverse early demineralisation are urgently sought. There have been considerable efforts to model dental erosion ex-vivo. These approaches typically expose animal or human tooth surfaces to an acid challenge and measure the resultant surface changes qualitatively through imaging [3, 4] or quantitatively through metrology and characterisation of surface micromechanical properties [5-8]. The two main limitations are (i) an inability to relate the specific variability of the hierarchically organised mineralised tooth structure (enamel prism orientation, size, hydroxyapatite crystallite size and texture, presence of substitutional ions within the mineralized tooth structure) (ii) difficulties in monitoring the sequence of dissolution and its impact on structural integrity in real-time.