Figure 3.

Schematic illustration of pellicle samples 8 h after a mild erosive attack ((a); e.g., agents with pH-values below 5) and after application of stannous-containing agents with low pH-values ((b); pH-values below 5). Mild erosive attacks lead to the formation of areas with a subsurface pellicle (a,b). Thereby, demineralized areas are filled with proteinaceous structures. A basal, more compact protein layer, the so-called basal layer, can be found in direct contact to the hydroxyapatite crystals (a,b). In contrast to other fluoride containing mouth rinses (a), agents with stannous ions show accumulations of stannous ions at the hydroxyapatite surface and inside the subsurface pellicle (b).