PHOTOACOUSTIC NON‐DESTRUCTIVE EVALUATION AND IMAGING OF CARIES IN DENTAL SAMPLES

Dental caries is a disease wherein bacterial processes damage hard tooth structure. Traditional dental radiography has its limitations for detecting early stage caries. In this study, a photoacoustic (PA) imaging system with the near‐infrared light source has been applied to postmortem dental samples to obtain 2‐D and 3‐D images. Imaging results showed that the PA technique can be used to image human teeth caries. For non‐destructive photoacoustic evaluation and imaging, the induced temperature and pressure rises within biotissues should not cause physical damage to the tissue. For example, temperature rises above 5 °C within live human teeth will cause pulpal necrosis. Therefore, several simulations based on the thermoelastic effect have been applied to predict temperature and pressure fields within samples. Predicted temperature levels are below corresponding safety limits, but care is required to avoid nonlinear absorption phenomena. Furthermore, PA imaging results from the phantom provide evidence for...

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