Usually in sci-fi teleportation is accompanied by some sort of pop, suggesting the air is displaced from the inside out. Since our body doesn’t physically expand and contract to a point sized speck too often, the energy to displace the material would need to be supplied from the teleportation device. Therefore, I’d suggest that any existing material is exploded outwards, depending on the capabilities of the device. Explode a rock? Maybe. Explode the core of a planet? Unlikely.