Dying tooth question

[LarLa]

Hello

I have an appointment at my dentist tomorrow to remove an old silver filling to see what's been happening with one of my 1st molars on the top. I chipped off a small piece of the tooth years ago and the dentist filled it down a bit so it wasn't sharp (x-rays, examination showed nothing other than the small chip on the inner edge). Around 6 - 8 months ago I bit something hard and had pain for a bit. I didn't really think anything of it as it went away but I asked my dentist at my regular appointment in May - she did xrays and looked closely at the filling and it looked fine. Dentist said it was probably ligaments around the tooth and they had healed. I ended up biting something hard again at the end of July and ended up with worse pain then I had before so I went back to the dentist. Xrays, exam, tap test, bite test were all good and she thought either inflammation or cracks in the filling. I was given a prescription mouthwash and told to come back in a week if it didn't get better. It got better at that time so I didn't go back until around 2 weeks ago when I had some pain again. They did xrays again (fine) and didn't see any obvious cracks in my tooth or filling. But I failed the cold test and was told the nerve in the tooth was dying. They can't really see what's going on until the filling is removed and hopefully then the tooth can be saved with a root canal. She did mention that if they find a crack below the gumline then it would be an extraction (I've been stressing about that ever since honestly).

What could have made my tooth die like that? I have other old fillings that I ask about at every appointment to have checked and they look good. Could the filling have gotten loose over the years? Is it a cracked tooth? The tooth isn't loose and isn't typically in pain. It does feel sensitive sometimes when I run my tongue over it. This is my first root canal and I'm a little freaked out. Tks.

 

[honestdoc]

Every tooth has a fragile nerve that can get traumatized and injured. Having a filling/dental work or getting hit in the mouth can injure the nerve. When the nerve gets injured, it can get better (reversible pulpitis) or become permanently damaged (irreversible pulpitis) or die (necrosis). It seems that you are injuring your tooth frequently so hopefully you and your dentist can figure that out.

 

[MattKW]

Teeth can "die" from deep decay, or cracks, or trauma (hit in mouth). Most cracks occur in teeth that have been previously weakened by decay and fillings. Cracks do not show up on Xrays - they are usually diagnosed by your symptoms and history of the tooth.
A negative cold test means that the nerve (pulp) has died. If there is a crack, then as long as it doesn't go below the gum surface then usually a Root Canal Therapy (RCT) and a crown will preserve the tooth. This is everyday dentistry and is no big deal apart from the cost and time involved. If the crack goes below the gum, then it would have to be extracted.

 

[LarLa]

Thank you for your answers. They did the first stage of the root canal not long after that post and my second appointment is this Wednesday. They did find a small crack under the filling but it wasnt below the gum line but Ill be getting a crown. The removed filling was apparently deep. I have been having some discomfort high on my gums by that tooth (at or near where the gum meets the lip). As far as I can tell it isnt red but its tender to touch. Hopefully it'll get straightened out on Wednesday.