I have a tooth, that on an xray shows what might be an abscess at the root level. This tooth has had a root canal and has a crown. Now the endodentist tells me that he will need to drill right thru the crown to treat/look at this abscess but there is a risk the crown will shatter. This is making me nervous as he did not elaborate on what will happen if this should occur. That is why I am seeking opinions.