i wouldnt worry about the crack. horizontal cracks can successfully be protected by a crown. if you are not experiencing discomfort quit worrying. you are mid procedure and the decision has been made. no use worrying about what ifs. the dentist has it under control.
Thank you so much for your help. I decided to get the tooth crowned and am right now with a temporary crown waiting for the permanent one to arrive.
I had another question. When I saw the shaved off tooth (before temp crown was placed) I could see a small horizontal crack towards the lower part of the tooth. Is that something I should be worried about? Also, my old filling broke off while the dentist was shaving off the tooth, and he had to redo it. I think this was the large filling on the right side (not the root canal filling). Would the crown be enough to protect this remaining tooth structure? The dentist decided not to put a post, he thought there would not be enough space for the crown.
I think the question is "will you have to get it crowned?" Did he fill the tooth after the root canal? If so, you would be okay with a veneer as there is less prep done to the tooth and crowns do develop bacteria and eventually the tooth can start to decay. So, being able to keep the tooth clean is important. But if he is saying that you can do a veneer for now but will eventually have to get the crown, go for the crown, otherwise it's twice the money.
crowns cover the entire tooth and offer more support. veneers are more brittle and offer less support. in the case of a root canal i would go with a crown. if you will be likely needing a crown in the future it might be more economical now instead of paying the same amount again in the future.