Please don’t say that, in fact I am thankful to you for your fast reply and for your patience.
Coming to your query? They are sensitive to mostly cold and yes the pain does last after it is removed.
Sensitivity to cold does indicates an inflamed pulp. The inflammation is considered REVERSIBLE if the pain from the cold stimulus disappears within a few seconds of removing the cold stimulus i.e. 15 seconds.
And if the pain from cold stimulus lingers on for 15 seconds or longer the inflammation is considered to be IRREVERSIBLE and it has proceeded to a situation where the nerve has died.
Also sensitivity to Hot on a tooth is a classic symptom of a dead nerve.
So, I was ruling out the possibility of dying nerve and need of root canal procedure, which your tooth does require!
Also, this type pain is often radiating and it pain cannot be manifested as confined to one tooth ,So to rule which teeth exactly needs the root canal i would suggest you get Pulp vitality tests done along with the x-rays before you proceed with the procedure.These tests are done by special instrument called Electric pulp tester which checks the tooth responses to cold and hot.
I would also like to suggest some treatment plan option. You can try the following low cost/free avenues and see if they work for you.
1) Try to contact your local dental state association for help. They can guide to find charitable organizations, discounted programs or dental foundations operating in your area that charge less or very minimal fee. You can find the contact details of your local dental society by following this links:
2) You can also contact a dental school nearby you; treatment rendered here is less expensive as compared to private dentists. Treatment is provided by dental students under the supervision of their skilled teachers and supervisors
I hope this helps!
Please ask me again if you have any remaining queries or doubts.
I wish you well.