Hello, Post filling sensitivity can be common. Persistant pain to cold raises the concern that you may need a bite adjustment. Do you feel that you hit the tooth first when you bite down or do you feel the tooth gets in your way when you slide your teeth? Call your dentist to verify your bite and make a slight adjustment if indicated. Your dentist will check your bite for high spots with a paper that marks how you bite down. Avoid chewing on the tooth, try to stay with a softer diet, brush with toothpaste for sensitive teeth and use fluoride rinses. If you have gum recession or inflammed guns around the tooth, this may be a contributing factor. Try the above suggestions. Be sure to continue good daily dental care and do not avoid cleaning the area. If you notice an increase in hot sensitivity and pressure sensitivity, this can indicate an abscess. Did your dentist warn you that the filling was deep and close to the nerve? Taking Antiinflammatory medication such as Tylenol or Advil may help reduce discomfort, but see your dentist to evaluate. A root canal may be necessary. If the filling is cracked or leaking this could cause cold sensitivity as well. Thank you for your inquiry. I hope my explanation is helpful.