Tuesday I had a crown replaced that had popped off the previous Saturday. There was no pain when I went into the dentist. He removed more of the tooth and made a new crown right then and there (which was quite impressive).
After the anesthetic wore off that day, the tongue began to hurt a lot. By Friday it still hurt and I called the dentist who said it was fine when I left, but to rinse with salt water 4x/day and avoid acidic food/drink. I'm also applying oral antiseptic a few times/day to ease the pain temporarily.
There is visual indication of a cut and sore. There is a line about 1 cm long that is not on the other side. There is also a small red area near it - both on the bottomside of the tongue.
I'm not sure whether to be concerned or just let it run its course.
I was told by a dentist that sometimes a red line can indicate infection. I would get an appointment right away with the dentist and if he can't see you please go to another dentist to double check, in case you need an antibiotic .
It could be that the retraction used to keep your tongue back while he prepped the tooth irritated or even cut your tongue or it may be irritated by the material he used to make the crown - is it a temp crown made of composite? Not too many drs make porcelain fused to metal in their office. I would follow his advice to rinse with warm salt water a few time a day but if it still bothers you in a week return and let him examine it - it could be the crown is too bulky near your tongue as well.
He made the porcelain crown right there in the office while I waited. Very cool to watch. Camera in the mouth, images on computer, designed the crown, sent to carving machine. 20 minutes later - new crown ready to go. No temp. That part impressed me. I just wish he didn't mess up the tongue. I've considered the possibility I bit it but was awake when the pain killer wore off, so that's doubtful.