Characterization of enamel in primary teeth by optical coherence tomography for assessment of dental caries

Caries is a disease that affects both primary and permanent dentitions, therefore new methods of caries diagnosis need to be tested on primary teeth as well as on permanent teeth.

This study reports the application of optical coherence tomography (OCT) to characterize sound dental structure and detect natural caries of human primary teeth.

Six primary teeth were sectioned into thin slices ( approximately 1.5 mm), and analysed perpendicular to the enamel surface by two home-made OCT systems operating around 1280 and 840 nm. The generated images were compared with histology as the gold standard.

We demonstrated the efficacy of the OCT technique to measure the depth of the enamel layer, whose result was statistically compared with histology (P = 0.823; P > 0.05) with good agreement. We also determined, through measurement of contrast values, an increase in backscattered intensity of the order of two to three times between sound and caries regions.

We employed OCT generated images to characterize the enamel layer. The technique showed great potential to be used on paediatric dentistry clinical on early caries detection with no pain, as it is a noninvasive method.