Confocal Raman microscopy and non linear microscopy to study human enamel incipient lesions

Incipient enamel lesions represent an early phase of dental caries. They can be produced in-vitro by pH cycling Raman spectral maps showed that the higher the organic/mineral ratio in the demineralized enamel, the lower is the intensity of mineral content in the same zone. Moreover, the evident red shift of the two-photon excited fluorescence (2PEF) spectrum from carious enamel, compared to that from sound enamel is typical of carious lesion formation. Second harmonic generation (SHG) signal was also observed in the lesion zone. The obtained results demonstrate a great potential for Raman, 2PEF and SHG photonic signals in diagnostic of incipient carious lesions.