Early diagnosis of dental pathologies by front face fluorescence (FFF) and laser-induced breakdown spectroscopy (LIBS) with principal component analysis (PCA)
Rihem Nouir, Imen Cherni, Hassen Ghalila, Sami Hamzaoui
Abstract
In dentistry, the early detection of lesions is not always obvious with traditional methods. It is necessary to develop new techniques, especially optical approaches, which are rapid for preventive detection. These developments are needed especially for developing countries. The objective of this work is to show how to take advantage of the decrease in fluorescence intensity associated with demineralization and to promote this technique for clinical use. For this purpose, front face fluorescence (FFF) based on the direct measurement of fluorescence was used. This study shows that it is possible to assess the presence of deposits and plaque by refining the discoloration of the areas. These analyses were reinforced by laser-induced breakdown spectroscopy (LIBS) to better understand the fluorescence changes with the mineral and trace element concentrations. The results demonstrate that fluorescence is suitable to estimate the onset of mineral loss in surface lesions. Indeed, the obtained results highlight the mineral loss in enamel surface lesions. The strong correlations between variations of certain regions of the fluorescence spectra with the intensities of calcium and phosphorus, obtained by LIBS, show the evolution of the deficiencies of these two elements from white to darker areas.