Looks like you've gotten more than enough responses to advise and confuse you, so i won't add to it.

Sensitivity to cold can be due to a variety of reasons: 1) recession and subsequent root exposure 2) dentin sensitivity from occlusal wear 3) old filling/restoration 4) caries or a cavity not extending to the nerve or pulp of the tooth 5) small fractures in the tooth surface. prolonged sensitivity to normal stimuli over 30 sec may indicate that the nerve of the tooth is inflammed or infected. an official diagnosis will need to take place with xrays and other tests conducted at the dental office to diagnose root canal necessity (infection of the nerve or pulp of the tooth).

Typically tooth discomfort from cold water does not indicate the need for a root canal. Many times it is due to root exposure or discomfort after a new filling is placed. If it does not improve in 2 weeks, I would recommend you seeing your general dentist. If you do not have one, we would be pleased to see you.

Not necessarily. Sensitivity to cold means the nerve is inflammed. At the early stages it could be reversible. I would suggest taking an anti-inflammatory medication such as Advil 3-4 times a day, plus use a desensitizing toothpaste, such as Sensodyne. If it doesn't help or seems to be getting worse, then the inflammation may be irreversible and you should have root canal therapy.

Sensitivity to cold can be annoying and frustrating. Determing the cause and options for treatment can only be done with an appointment since there can be several causes, some MAY result in the need for a root canal.

Dear Anonymous, There is a middle ground when it comes to sensitivity from cold water to a tooth. If the only time the tooth hurts is when cold water or drinks are used and the pain goes immediately away, then the patient could be suffering from tooth wear or abrasion at the gumline. If the tooth pain stays with the patient for a length of time or is accompanied with pain while eating, then the chances of root canal are much greater. A checkup and tooth sensitivy testing could determine which of these scenarios seem most reasonable. If the pain is just tooth sensitivity to cold, therefore, you could get away with just a filling or desensitization treatment.
I hope this explaintion helps.
Sincerely,
Dr. Roth