The impact of radiotherapy on endodontic treatment: a scoping review

This scoping review aimed to map how radiotherapy can influence endodontic treatment. The protocol of this review is available online ( https://osf.io/aq7fv/ ). The report followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. A structured search was conducted in PubMed, Embase, Scopus, and Web of Science up to September 2024. Studies that assessed the influence of radiotherapy on the interaction between endodontic sealers and root dentin, the biomechanical behavior of endodontically treated teeth, and the success rates of therapy were included. There were no restrictions on publication date or language, and in vitro studies, observational studies, and experimental clinical studies were eligible. Two researchers independently selected the articles and extracted the data. Out of 1748 studies identified, 18 met the inclusion criteria-13 in vitro studies and 5 observational studies. Most studies used fixed radiation doses, with radiotherapy administered before endodontic treatment. The results of the in vitro studies demonstrated that radiotherapy reduced the bond strength in all studies for at least one of the tested sealers, significantly increased the amount of residual filling material during retreatment and did not negatively affect apical sealing ability. Moreover, radiotherapy influenced the biomechanical behavior of both intact and endodontically treated teeth. However, the findings of observational studies regarding clinical success rates remain controversial. The reviewed evidence suggests that radiotherapy may impact endodontic treatment outcomes in the mapped contexts. However, the available data are limited and further research is needed to strengthen the evidence in this field.