I tried to replace a dimmer switch with no neutral wire with a new one with no neutral wire. The green wire touched the main plate and shorted out. Now none of the two other switches in the 3 switch box work. Nor a switch across the room. The circuit breaker works because other electric switches in the breaker still work. I tried putting back the old switch. Looks like no power to the wires. I even used a test light...the two black wires don't seem to have any power. Could I have shorted out another switch in the box so that power is being interrupted?
You need to turn the breaker for the circuit completely off then back on to reset the breaker to be closed. Do that after you are sure there are no loose wires to cause a short again. If the resetting of the breaker does not work, the circuit is probably protected by a GFI outlet that has opened. That GFI will have to be reset as well.
Like RMDman said, if it's not the breaker, it might be a GFI/GFCI that could have tripped. I had the same issue a while ago and found a "dead front" GFCI in a closet I had to reset.
Also, more recently, I replaced a couple of outlets (on the same outdoor circuit) that lost power after I worked on them. I had to get an electrician to find the issue, and they found a GFCI outlet that refused to reset. After replacing it, the circuit worked again.
As a side note, I didn't remember this outlet existing because it was behind some shelving in the garage. They had to trace the wiring with a tone generator to locate it. Also, it doesn't really make sense to me that an outdoor outlet was on the same circuit as an outlet in the garage, but I'm also not an electrician.
I'm not saying GFI/GFCI are bad or anything, just that they might be the culprit in more ways than one. Also, look everywhere for for these things. They might be in a weird or illogical place.