Enamel diffusion modulated by Er:YAG laser: (Part 2). Organic matrix

Organic matrix (OM) has been hypothesized as a key player in the laser-induced retardation of enamel diffusion (LRED). Objectives Therefore, this study was aimed to quantify the contribution of OM in LRED. Methods Four groups of enamel sections (n = 10) were assigned to ‘normal’, ‘laser treated’, ‘OM extracted’ and ‘laser + OM extraction’ groups for measurement of diffusion coefficient (DC) using fluorescence recovery after photobleaching (FRAP) and fluorophores transport study (FTS). Er:YAG laser treatment and OM extraction were performed on respective groups. Sections were characterized with stereomicroscopy and polarized light microscopy. Treatment effects were statistically assessed with a factorial ANOVA. Results DC measured by FRAP and FTS coupled with confocal microscopy revealed the significant effect of OM (p = 0.001) and laser treatment (p < 0.01). After OM extraction, the laser effect on diffusion decreased about 34–75%, confirming the significant role of OM in LRED. Conclusion Both FRAP and FTS may be promising tools to quantify enamel DC.