Why do i have sensitivity on a crowned tooth when i floss or suck in cold air? the crown was placed 4wks ago. it doesn't hurt otherwise.

Have ur dentist look: It just may be that the tooth is a little sensitive after being worked on. Diamond burs cutting into teeth can be a bit traumatic. Have your dentist check all of the margins to be sure they are sealed.

Exposed margins: That may means that the crown margins are shorter than the prepared tooth surfaces,specially interproximally (between teeth) , is the tooth root canal treated? ,also if the crown is slightly higher than the rest of your teeth( in other words,does it touch your opposing teeth first before the rest of the teeth touch?) that also might be a factor. Call your dentist and have it looked at for adj.

See your dentist: If your tooth has not had a root canal it will still contain the nerve and therefore have some temporary sensitivity to cold. If you notice pain or sensitivity when you bite down, contact your dentist for a minor adjustment. Regardless if it is a high occlusal contact or an open margin, see your dentist for an evaluation and x-rays. Sometimes no treatment is the best treatment.