crown removal procedure

I recently had a crown removed by a new dentist.  It needs to be replaced due to my gum receding & exposing the bottom line of the crown.  It's my #18 - bottom left molar - no wisdom teeth so it's the last one on that quadron in the back of my mouth.  He tried to use what I would call a 'hammer & chisel' method at first against the existing crown which didn't work & finally brought out the drill.  I believe he banged that thing against my old crown about a dozen times and I just want to find out if this is a normal procedure to remove the crown or not?  

I would greatly appreciate and advise or insight you can offer me.  Thank you.  Annette