Not sure what to do regarding restoring cracked molar

[Moonchilde@2714]

I have a bottom molar with a large silver filling in it that is 55 years old. The tooth has two vertical hairline cracks that extend to the gumline on the tongue side. The dentists I have seen do not seem to know if the cracks extend under the gumline, they do not show on the x-rays. I do not have any pain to biting pressure or release. I only have mild intermittent aching and previously, sharp sensitivity to cold but I put clove oil, and that cold sensitivity went away. I also have periodontal disease and some mild gum recession. I was given advice from two dentists. The first said take out the filling, examine the tooth, and cut out the cracks and replace the filling with composite. She said that might solve the problem entirely, or if not, I might still need a crown and/or root canal. The second dentist said go straight to temporary crown and wait to see if still symptomatic and root canal is needed. Either way the filling has to come out I assume. I am not concerned about the money here as the dentist who recommends the filling is very expensive and costs more for a filling than the other dentist charges for a crown. I would choose to have the filling replaced and cracks cut out because I would rather try to keep my tooth structure before placing a crown, I would hope that placing a filling would be sufficient. But cutting out cracks sounds worse for the tooth (although the first dentist says a crown would be more likely to lead to root canal). Am I making the wrong decision?

 

[Dr M]

If the current filling is indeed large, then cutting out the cracks, will only further reduce the amount of sound tooth structure left in any case. So it sounds like a crown is the way to go.
I would recommend the temp crown. Especially if the filling at the other dentist is more expensive. Wear the temp crown for at least a month, to observe for any symptoms.
There is a chance that the tooth might require a root canal in either scenario, depending on how deep the crack goes. There is also a chance, that if the crack extends to deep, perforating the pulpal floor or the root of the tooth, that none of these options would work, and then an extraction, with a suitable replacement, would be the only course to follow.

 

[Moonchilde@2714]

I am curious, if the crown is placed, will the dentist remove the filling or leave it in place ?

 

[Dr M]

Most likely the entire filling will be removed, since the crack needs to be drilled out. You can then build up a core with composite or glass ionomer instead.
Keep in mind, my opinion is based on the information given by you. I don't have a clinical picture or x-ray of the tooth.

 

[Dental cure and care]

You mentioned mild intermittent aching and previously sharp sensitivity to cold that improved with clove oil application. This suggests some degree of pulp irritation or inflammation but not necessarily irreversible damage at this point.
Based on your symptoms and dental history, it seems prudent to follow through with Option 1—removing the filling for direct inspection before deciding on further treatments like crowns or root canals based on what is discovered during that process.