Once a crown is cemented, there are only two alternatives to drilling through the crown. Your dentist could attempt to remove the crown without damaging it although this possibility is highly unlikely. The second alternative, which is the most invasive, would be to access the root at the bottom of the tooth by going through the gum and bone. After making an access hole through your crown, your dentist will place a permanent filling. Although you may not like the idea of your dentist drilling through your crown, this option would be the least invasive and the crown should be expected to last for year after with proper maintenance. Good luck and I hope this helps! Click "save" under my name, if you'd like to ask me more questions in the future.