Effect of therapeutic fractionated radiotherapy on bond strength and interfacial marginal adaptation of Adseal, MTA Fillapex, and EndoSequence BC sealer: An in vitro study

[摘要] Introduction: The study aimed to assess the impact of fractionated radiation on push-out bond strength of sealer to dentin interface and on marginal adaptation of the sealer (Adseal, MTA Fillapex, and EndoSequence BC sealer) to irradiated dentin. Materials and Methods: Ninety maxillary central incisors were randomly divided into two groups: with irradiation (n = 45) and without (n = 45). All the samples to be radiated were exposed to fractionated dosage (60 Gy) through Co-60 gamma (1.17 and 1.33 Mev) photons. Specimens were prepared and subdivided into three subgroups (n = 15 each) according to assigned sealer Adseal, MTA Fillapex, and EndoSequence BC sealer. Later, the samples were sectioned into a 1 mm thick segment at each root third for bond strength and scanning electron microscope (SEM) analysis. SEM micrographs were analyzed with an ORION version 6 image analyzer. The percentage of failure mode after debonding was evaluated with a stereomicroscope. Bond strength data were analyzed using two-way analysis of variance and the Tukey's post hoc test. Results: Bond strength was significantly (P < 0.0001) decreased after radiotherapy (0.76 ± 0.12 Mpa) versus without radiation (0.93 ± 0.18 Mpa). Furthermore, when the pooled average of sealers was compared, significantly highest bond strength was perceived in Adseal (0.98 ± 0.18 Mpa) followed by EndoSequence BC (0.84 ± 0.13 Mpa). Coronal sections showed significantly (P < 0.0001) higher bond strength (0.99 ± 0.16 Mpa) compared to the middle (0.81 ± 0.14 MPa) and apical third (0.74 ± 0.12 Mpa). Qualitative SEM revealed a higher interfacial gap between sealer and irradiated radicular dentin. The percentage of mean change was recorded significantly high in MTA Fillapex (52%), then in EndoSequence BC (31%), and least was in Adseal (17%). Conclusions: Irradiated teeth resulted in consequential decreased adhesiveness and bond strength of dentin to root canal filling material. In addition, the highest bond strength was noticed in Adseal.

[学科分类] 口腔科学

[关键词] Bond strength;interfacial gap;irradiated dentin;radiotherapy;root canal sealer