When should root canal therapy with calcium hydroxide be initiated for avulsed mature teeth?

The initiation of root canal therapy with calcium hydroxide for avulsed mature teeth is optimally performed around 7-10 days after the injury. This timing allows for the initial healing processes to take place following the avulsion, which is crucial for the recovery of the periodontal ligament (PDL) that may have been compromised during the tooth's avulsion.

After replantation, it's important that the tooth has time for the PDL to potentially recover, thereby allowing for a better chance of successful healing without immediate endodontic intervention. Initiating treatment too soon (like immediately after replantation) might not allow sufficient time for the PDL to stabilize and can negatively affect healing outcomes.

Similarly, initiating treatment at the first evidence of root resorption is usually not recommended as this could lead to premature intervention, which may not allow full assessment of the tooth's vitality and the healing potential of the PDL. Performing root canal therapy before replantation could jeopardize the tooth's chance of survival, as vitality of the surrounding tissues is paramount during the healing phase.

Thus, waiting for about a week to ten days ensures that a careful evaluation of the tooth’s condition can be made, allowing the clinician to determine the appropriate timing for root