Laser scanning microscopy of enamel and dentin sections with two-photon fluorescence and second harmonic generation

In this study, we have demonstrated the use of two-photon fluorescence and second harmonic (SH) generation in imaging the enamel and dentin sections. In addition, microspectroscopy is employed to identify the origin of two-photon fluorescent and SH signals, which are attributed to hydroxyapatite crystals and collagen fibrils, respectively. Hydroxyapatite is found to be present throughout the sections while collagen fibrils only exist in the dentin and dentinoenamel junctions.