Antibiotics cannot cure a root canal infection because the source of the infection is inside the tooth where there is no blood supply; without blood supply there is no mechanism to deliver antibiotics. The cure is the complete shaping, cleaning and obturation (sealing) of the contaminated root canal space.
Thanks for the A2A, Joseph Boyle. You've already gotten plenty of answers, but since they differ a bit, I may as well cast my vote. According to http://Space.com The minimum distance from the Earth to Mars is about 54.6 million kilometers. The farthest apart they can be is about 401 million km.
First the short answer. Mars has an average distance from the Sun that is about 1.5 times that of the Earth's average distance from the Sun. This means that when Earth and Mars are closest to each other, the distance would be about 1.5 - 1.0 =0.5 times the average distance of Earth from the Sun. When Earth and Mars are on opposite sides of the Sun, the distance between would be about 1.5 + 1.0 = 2.5 times the average distance of the Earth from the Sun.