Hi dr how long does it take for my breast bone to heal after a CABG surgery?

CABG. The breast bone will take a minimum of 6 weeks to heal solidly. Generally I advise my patients to give it more time than that before doing exercise that can stress the line healing. At least 8 weeks is probably prudent to be conservative. Usually it doesn't hurt for the whole 6 weeks however. Generally the pain is significantly decreased by two weeks.
Depends. Depends on what you mean heal. The external incision heals quickly-sealing up within 7-10 days. The breastbone is sutured together in the operating room with high tensile strength steel wires that hold the two sternal halves in proximity while the healing occurs. The breastbone will firm up within about 6-8 weeks following surgery.