A Comparative Study of the Photosensitizer Penetration into Artificial Caries Lesions in Dentin Measured by the Confocal Raman Microscopy.

This study utilized the confocal Raman microspectroscopy ( CRM) technique for the first time to investigate the degree of the penetration of toluidine blue-orto ( TBO) in artificial caries lesions produced by two distinct caries-inducing models. The dentin specimens ( n = 10) were divided into three groups: control, in vitro and in situ. Thereafter, the lesion depth and the demineralization level were evaluated by cross-sectional microhardness ( CSMH). CRM mapping across the dentin surface was assessed after the dye application. The CSMH and CRM data were analyzed by t-test and ANOVA, respectively ( P < 0.05). The values of the lesion depth and the demineralization areas were higher for in situ samples ( P < 0.05). The TBO penetration values (μm) for the control, in vitro and in situ groups were 44.8 ± 5.6, 46.1 ± 4.5 and 51.2 ± 8.5, respectively. There were no statistically significant differences among the groups ( P > 0.05). The rate of TBO penetration was detected up to about <50 μm and the demineralization level did not influence the results. These results have showed promising parameters to develop new protocols for deep caries lesions management using photodynamic antimicrobial chemotherapy. [ABSTRACT FROM AUTHOR]