The importance of the coronal seal following root canal treatment.

Although a plethora of research on coronal microleakage does not exist, the studies do confirm that a sound coronal seal is of paramount importance to the overall success of root canal treatment. Temporary restorations provide an adequate seal provided they are used correctly and only for a short time. The best rule of thumb is as follows: a properly cleaned, shaped, and obturated tooth should be permanently restored as soon as possible. If the clinician suspects coronal microleakage has occurred over a time period of 3 months or more, retreatment of the root canal should be performed before placement of a permanent restoration. The clinical significance of coronal recontamination over a time period of 1 to 3 months is more ambiguous; the existing conditions of each individual case will determine whether retreatment is necessary. Continued research, especially with in vivo models, is needed in this aspect of endodontics.