Multiphoton Micorsocopy Investigation of Tooth Structure

Objectives: To investigate tooth structure with multiphoton microscopy to acquire high resolution biomedical images without any decalcification procedures. Methods: Human tooth was sectioned and observed and two-photon excited autofluorescence and second harmonic generation (SHG) images were obtained using two photon microscopy. Submicron resolution images of the enamel, dentin, and the periodontal ligaments were obtained by combing autofluorescence and second harmonic generation (SHG) images . Results: The structure of enamel rods were demonstrated under endogenous two-photon autofluorescence signals. The structure of the dentinal tubules are visible in both the AF and SHG images. The periodontal ligament composed of mostly collagen is visible in the SHG images. Three dimensional images of the enamel, dentin, and periodontal ligament from sequences of images were constructed.. Conclusion: Our studies demonstrate that the spectral contrast offered by multiphoton AF and SHG miocroscopy can be used as an effective tool for the investigation of tooth structure.