The principle of choosing treatment plan for the affected teeth after removal of previous restorations based on the endodontic and periapical situation

Restoration of teeth after removal of previous restorations is a common problem in the dental clinic. The situation of teeth after removal of previous restoration is complex and often requires multidisciplinary cooperation. However, there is a lack of systematic and concise guidelines for determining the treatment plan for those teeth. Through a combination of restorative clinical experience and the opinions of endodontic specialists, the author systematically described the problems that may exist after the removal of previous restorations in the teeth that have not undergone or have undergone root canal treatment (RCT) and those with post and core restorations. And summarized the corresponding treatment recommendations according to their pulpal and periapical status, the quality of RCT and the presence or absence of post and core restorations. ①For teeth without RCT, the vitality of the pulp, the occurrence of pulpal/periapical disease and the amount of re-preparation need to be assessed to determine whether RCT is necessary. ②For teeth with RCT, if the quality of RCT is good and no periradicular lesion exists, direct restorative treatment can be considered. If the quality of the RCT is unsatisfactory but no periradicular lesion exists, root canal retreatent (re-RCT), follow up or direct restorative treatment should be performed as appropriate and treatment plan can be developed in conjunction with the endodontist if necessary. If the quality of the RCT is unsatisfactory and periradicular lesion exists, re-RCT is necessary before restorative treatment.③For teeth with post and core restorations, if the quality of RCT is good and no periradicular lesion exists, direct restorative treatment can be considered. If the quality of the RCT is unsatisfactory but no periradicular lesion exists, follow up or direct restorative treatment should be performed as appropriate and treatment plan can be developed in conjunction with the endodontist if necessary. If the quality of RCT is unsatisfactory and periradicular lesion exists, for teeth with thin post and thick root canal walls, re-RCT after removal of the post can be attempted. For teeth with thick post and thin root canal walls, preservation of the post and apical surgery can be considered. For the teeth with excessively large defects or extremely poor periodontal conditions, extraction is recommended. The author refined the above recommendations into a set of treatment procedures, aiming to provide a reference for the selection of treatment options for teeth after removal of previous restorations.