Fig. 2

Representative SEM images showing morphology of dentin surface after different energy treatments. a Control group, b acid etching group, arrow indicates opened dentinal tubules, c 50 mJ laser group, arrow indicates protruding out of the peritubular dentin, d 100 mJ laser group, arrows indicate fish-scale and lamellar dentin, e 150 mJ laser group, arrow indicates periodontal dentin cracks, f 200 mJ laser group, arrows indicate peritubular dentin deep cracks, g 250 mJ laser group, arrow indicates disappearance of the fish-scale and lamellar morphology, h 300 mJ laser group, arrows indicate the collapsed tissues between the dentin tubes, coking, or carbonization