Statistical analysis The data were processed using Statistical Package for Social Science (SPSS) software version 19.0 (SPSS®: Inc., Chicago, IL, USA). The chi-square test (significance level of < 0.05) was used to determine differences between the success rates of Biodentine and MTA. Fisher's exact test (a subdivision of the chi-square test) was also used when two cells had an expected count of less than 5.