Figure 7. Modified SEM image of bonding to dentin with one-bottle (two-step) total-etching adhesives. (A) Acid-etched dentin (blue). (B) Application of the primer/adhesive mixture. The organic solvents used in these mixtures (green) quickly displace water in the collagen network because of the diffusion gradient they create between the water of the collagen and solvent in the bonding agent. Therefore, the incorporation of the primer and the bonding resin inside the collagen network can occur simultaneously.