Fig. 4

Representative SEM images of the 0 wt% hCS (A) and 52.5 wt% hCS (B) immersed in artificial saliva for 15 d (upper left), 30 d (upper right), 60 d (lower left), and 90 d (lower right) at magnifications of 500×. The main images show the surface of specimens, and the smaller images at the upper right are images of the cross sectioned specimens. Representative SEM-EDS images of upper and cross-sectioned surfaces of 0 wt% hCS (C) and 52.5 wt% hCS (D) immersed in artificial saliva for 90 d at magnifications of 500×. EDS results indicate Al as yellow, Si as green, Ba as grey, Ca as red, and P as blue