All temporary fillings must be replaced to prevent leakage and possible reinfection or contamination of the completed root canal.
The existing root canal may be failing after many years. The tooth may be able to be re treated with a successful outcome. Other options would be to extract the tooth and place an implant if the root canal has a poor prognosis.
Dilute the peroxide to one half using water to prevent irritation of the wound. Salt water is the preferred rinse for implants and extractions as directed by your dentist.
