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Influence of therapeutic cancer radiation on the bond strength of an epoxy‐ or an MTA ‐based sealer to root dentine
Author(s) -
Martins C. V.,
Leoni G. B.,
Oliveira H. F.,
Arid J.,
Queiroz A. M.,
Silva L. A. B.,
SousaNeto M. D.
Publication year - 2016
Publication title -
international endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.988
H-Index - 119
eISSN - 1365-2591
pISSN - 0143-2885
DOI - 10.1111/iej.12556
Subject(s) - epoxy , bond strength , materials science , composite material , dentistry , medicine , layer (electronics) , adhesive
Aim To evaluate the influence of radiation on root canal sealer push‐out bond strength to dentine and sealer/dentine interface in teeth filled with AH Plus (Dentsply Ind. Com. Ltda, Petrópolis, RJ , Brazil) and MTA Fillapex (Angelus Ind. Prod. Odontológicos S/A, Londrina, PR , Brazil). Methodology Thirty‐two maxillary canines were selected and randomly assigned to 2 groups ( n = 16): one group was not irradiated, and the other was subjected to a cumulative radiation dose of 60 Gy. Root canals were prepared with the Reciproc system ( VDW GmbH, Munich, Germany), and each group was divided into 2 subgroups ( n = 8) according to the sealer – AH Plus or MTA Fillapex – using the single‐cone filling technique. Then, 1‐mm‐thick dentine slices were obtained from each root third for the push‐out test to evaluate sealer bond strength to dentine and for scanning electron microscopy ( SEM ) to examine the sealer/dentine interface. Failure mode after debonding was determined with a stereomicroscope at ×25 magnification. Bond strength data were analysed by two‐way anova with a split‐plot design and post hoc Tukey's test (α = 0.05). Results Significantly lower bond strength ( P < 0.0001) was obtained after irradiation (0.71 ± 0.20 versus 0.97 ± 0.29 MP a) and in specimens filled with MTA Fillapex (0.70 ± 0.18 MP a) compared with AH Plus (1.00 ± 0.27 MP a). Percentage of adhesive failures increased after radiation in all root thirds in the teeth filled with AH Plus. SEM revealed more gap‐containing regions and fewer tags at the sealer/dentine interface in irradiated specimens, with more tag formation and fewer gaps with AH Plus sealer. Conclusions Radiation was associated with a decrease in the push‐out bond strength of sealers to intraradicular dentine and formation of more gaps and fewer tags at the sealer/dentine interface regardless of the sealer.