Can radiotherapy affect the apical sealing ability of resin-based root canal sealers?

Background. The authors conducted a study to assess the influence of radiotherapy on the apical sealing ability of one recently introduced resin-based root canal sealer and two sealers that have been in use for several years. Methods. The authors divided 90 human maxillary anterior teeth into three groups according to the type of root canal sealer used and, using lateral condensation, obturated the roots with gutta-percha. They randomly divided all roots into two main groups according to the presence or absence of radiotherapy. For the groups that received irradiation, a dose of 60 gray was delivered in fractions of 1.8 Gy per day, five days a week for seven weeks. The authors then performed the centrifuging dye penetration test to determine apical leakage for each specimen. Results. The authors compared the specimens in the groups that received radiotherapy after endodontic treatment with the specimens in the groups that did not undergo radiotherapy after endodontic treatment. They found that mean apical leakage was slightly higher in the radiotherapy groups, but they did not observe any statistical difference between the groups (P > .05). In the groups that did not undergo radiotherapy, the mean apical leakage for the specimens in the MM-Seal (MicroMega, Besancon, France [not marketed in the United States]), AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany) and AH 26 (Dentsply DeTrey GmbH) groups was 2.52 +/- 0.42 millimeters, 2.85 +/- 0.52 mm and 3.73 +/- 0.41 mm, respectively. In the groups that underwent radiotherapy, the mean apical leakage for the specimens in the MM-Seal, AH Plus and AH 26 groups was 2.72 +/- 0.55 mm, 2.96 +/- 0.47 mm and 3.93 +/- 0.61 mm, respectively. Conclusion. The apical sealing ability of the resin-based root canal sealers decreased slightly when radiotherapy was administered, although there was no statistically significant difference. Clinical Implications. Clinicians can safely use a resin-based root canal sealer in patients receiving radiotherapy.