Objectives: The current study was carried out to (1) evaluate premixed bioceramic (BC) and mineral trioxide aggregate (MTA) sealing properties in a laboratory and (2) compare the performance of these two materials in repairing an immediate iatrogenic furcal perforation of primary molars both clinically and radiographically.Materials And Methods: In vitro sections including eighty mandibular second primary molars were sorted into 4 equal groups: (1) an intact furcation area group, (2) an artificial perforation group (unrepaired), (3) an artificial perforation group repaired with MTA, and (4) an artificial perforation group repaired with premixed BC. The dye extraction method was used to assess the sealing ability of the material.