The aim of the study is to assess cytotoxicity and push- out bond strength and mode of bond failure of two bioceramic- based root canal obturation systems; EndoSequence and SmartSeal. For cytotoxicity evaluation; extracts of both materials in fresh (cone or sealer) and set (cone + sealer) states were serially diluted to 11dilutions, and brought in direct contact with cultured MRC-5 for 1, 3, and 7 days. MTT assay was performed, viable cells were counted using ELISA reader, and cell viability percentage was calculated. Bond strength evaluation: two groups of single rooted teeth (n=16) were sterilized. Access cavity was prepared in each tooth followed by mechanical preparation using rotary Ni- Ti EndoSequence files up to final file size of #40 or #45. Each of the test groups was obturated using one of the tested obturation materials utilizing single cone technique. Teeth were molded in self cure acrylic resin. Slices of 1 ±0.1- mm thickness were obtained; 3 from each specimen (apical, middle, and coronal). Push out test was performed using universal testing machine, the results were recorded and calculated. Tested sslices were examined under optical microscope to assess bond failure mode. Cytotoxicity results showed that all test groups exhibited slight cytotoxicity at all time intervals regardless of the concentration. All groups showed severe cytotoxicity at 1/2 dilution at all time intervals, then become moderately and slightly cytotoxic on increased dilution. At lower dilutions; 1-day interval showed higher cytotoxicity than 3 and 7days intervals of same dilution. SmartSeal recorded significantly total higher mean push out bond strength than EndoSequence. As compared slice position; SmartSeal recorded significant higher mean coronal and middle values. Final file size comparison showed that; the total file size effect was non significant while there was a significant difference related to the sealer and the area. Bond failure mode was found to be adhesive for both sealers.