Fig. (2) Schematic diagrams sequentially show the specimen preparation, secondary carie induction, and observation using a fluorescence microscope (FM). Class-1 type cavities were prepared, immediately restored with resin composite, followed by S. mutans biofilm formation using an oral biofilm reactor (OBR). Specimens were then rinsed once daily with the antiseptic mouthwash solutions during the final 7-day incubation period. Location of the measured lesion area is indicated.