“How long should a deep filling hurt?”

Occasional sensitivity to cold can last months on a deep filling. Use OTC pain pills as needed. Hot sensitivity should decrease in a few days. If not getting better to hot, the nerve may not recover, in which case it can be removed by an endodontist. Pressure sensitivity to biting can be adjusted by your American Dental Association dentist any time. Use OTC meds as needed and give your tooth time to heal by itself, but don't let it keep you up at night.

Russell A. Sassack, D.D.S. 

1-2 weeks is normal, but if it continues, see your dentist or endodontist

It may hurt for a few days, a few weeks, a few months, or it may never go away. If it doesn't go away in a few weeks, most likely you will need a root canal.

A deep filling is one that is close to or right at the nerve. Generally, we would expect some soreness or pain after repair of a deep cavity. Your nerve needs time to heal. However, you should notice an improvement in symptoms/pain every day or so if your nerve is doing well.

If you wait for 5-7 days, and there is no improvement in symptoms, this could be a sign that your nerve is not going to heal or "settle down". Given that the only alternative is root canal treatment, we often encourage patients to wait 2-3 weeks if they can manage it to give a proper amount of time for nerve healing.

Post-filling symptoms are due to inflammation and so NSAID medications (such as ibuprofen) tend to be superior in providing comfort when compared to Tylenol. Of course, you'll want to make sure that you can safely take NSAIDs like Ibuprofen first.