You should not chew or bite on the treated tooth until you have had it restored by your dentist. The unrestored tooth is susceptible to fracture, so you should see your dentist for a full restoration as soon as possible. Otherwise, you need only practice good oral hygiene, including brushing, flossing, and regular checkups and cleanings.
Most RCT treated teeth last as long as other natural teeth. In a few cases, a tooth that has undergone RCT does not heal or the pain continues. Occasionally, the tooth may become painful or diseased months or even years after successful treatment. Often when this occurs, redoing the RCT can save the tooth.