Objective The aim of this study was to evaluate the viability of stem cells from exfoliated and deciduous teeth (SHED) on dentin surface treated with triple antibiotic paste or calcium hydroxide. Materials and Methods Nine single-rooted extracted premolars were prepared appropriately and divided into three groups. In group A, the root canals were left empty, a triple antibiotic paste was placed in the root canals of group B, and calcium hydroxide was placed in the root canals of group C. After 1 week, the intracanal medicaments were removed, and stem cells were seeded on the treated surface of the specimens for 1 more week. The cells were stained and then observed under confocal microscope over the entire surface of each test material. Counting of the cells was made by Image J (3D) software, as well as manually. Statistical Analysis To investigate any statistically significant differences between the experimental groups, statistical tests including Kruskal–Wallis and Mann–Whitney U-test were performed. Significance level was set to P < 0.05, and all analyses were performed with SPSS IBM program, v. 21. Results Groups B and C showed statistically significantly higher number of cells compared to Group A, whereas cells developed in a substrate of calcium hydroxide residues appeared in majority with distinct cores and widened unlike other groups. Conclusions The effect of calcium hydroxide manifested better results regarding the number of stems cells on root canal surfaces.

In Discussion, paragraph 5, sentence 5 should read: This contrasts with the existing view that the use of Ca(OH) 2 in regenerative endodontics may be questionable because of the potential toxicity to human cells. 29