Figure 2. In vivo diffusion through dentin of a solution of silver nitrate. (A) Diffusion of silver particles (arrows) across dentinal tubules 35 min after the application of a silver nitrate solution () inside the cavity (HE staining x 40). (B) Penetration of silver particles () into the pulp area and into the capillary system active at clearing the pulp (HE staining x 40).