Figure 5 showed CLSM images of the live/dead staining of different groups on the dentine surface after 48 h. The red-to-green ratio of Groups 1 to 4 were 0.12 ± 0.05, 0.19 ± 0.05, 0.11 ± 0.04 and 0.04 ± 0.02, respectively (p = 0.001). Multiple comparisons showed that the red-to-green ratio of Group 4 was smaller than that of the other groups, and the largest red-to-green ratio was shown in Group 2.