Imaging and quantitative analysis of early caries using optical coherence tomography

OBJECTIVE: To explore the efficacy of optical coherence tomography (OCT) in imaging and quantitatively evaluating early enamel caries and provide experimental evidence for the clinical diagnosis of early caries.

METHODS: The smooth surface of bovine teeth showing early artificial caries and demineralization changes was scanned by an all fiber-based OCT for images and optical profiles, which were compared with images from a polarized light microscope (PLM) and mineral loss from an atomic absorption spectrometer. Data were analyzed by paired-sample t-test and Pearson correlation analysis using SPSS software.

RESULTS: The images of enamel with early caries and demineralization from OCT coincided with those from PLM. The integrated reflectivity loss in the early caries group was significantly lower than that in the demineralized group (P < 0.05), whereas no significant difference in demineralized depth was found between the two groups (P > 0.05). A linear correlation was observed between integrated reflectivity loss and mineral loss (P < 0.05).

CONCLUSION: OCT can be used to nondestructively and accurately image early caries and quantify lesion extent and degree, suggesting the extensive use of this approach in the clinical diagnosis of early caries.