Fig. 3: Representative surface images by SEM at a magnification of 25,000× in backscattered electron mode (material contrast) of treated dentin samples (from left: A2, B2, C2).
From: Dentin tubule occlusion by a 38% silver diamine fluoride gel: an in vitro investigation

Occluded tubules are visible in 3a and 3c; open tubules are visible in 3c. Scale bar 2.5 µm.