My back molar has cold sensitivity now on a gold crown?

Absolutely: Gold is an excellent conductor of thermal changes induced by cold or hot fluids/foods. If it responds to room temperature, it could be more serious. Inflammation in the central tissues of the tooth might have been caused by the procedure which should decrease with time. If the inflammation is induced by bacteria, there is a possibility that the problem may persist or worsen. Return to dentist.

For how long?: Some sensitivity is common after dental work, regardless if the crown were made out of gold, porcelain fused to metal or completely out of porcelain. If the sensitivity is mild and has been getting better, then that's a good sign. If it's not getting better or is getting worse, you should contact your dentist for further tests.

Can happen: Gold is a thermal conductor and can transfer that to the tooth. If it is an old one, there might be leakage. Speak to your Dentist . Good Luck.

See your dentist: for evaluation, x-rays and treatment if needed.

More info needed..: New crown or old crown? How old? Last dental check-up? Cold sensitivity could be cavity or gum recession. Please make an appointment with a local dentist for a definitive diagnosis.