What can i do for cold sensitivity after tooth extraction?

Several things: First keep the extraction site clean to allow complete healing to cover the roots of the adjacent teeth. Exposed roots can be treated with a Fluoride varnish if it continues. Sometimes decay exists on the adjacent roots that needs repair. Bacterial induced inflammation of the tooth central tissues may or may not heal over time. If it persists, see your dentist, have pulp vitality test and xray.

Avoid Cold: Not forever. Most of the time, cold sensitivity after extraction is from the adjacent tooth. When a tooth looses the insulation that the adjacent tooth provides, the exposed root surface and tooth surface can sometimes be sensative to cold. Usually this is temporary however if a large defect exists at the extraction site, dental intervention may be necessary. Try sensodyne toothpaste 2 weeks.