So on one of the extras one of the Russos state that Thanos permanently damaged the Gauntlet and himself when he did the snap. And since I just got the 4K and am able to really look at it the Gauntlet looks totally messed up. He was still able to use it to teleport away but I bet no one could undo the snap with it, even Thanos if he wanted to, which he wouldn't.
I noticed the Gauntlet was messed up in the theater, last night I noticed that his left arm and side were still messed up after he teleported away, but the wound in his chest seemed healed.
Also, he teleported away so that must mean he was still able to use the stones, right?