Impact of radiotherapy on the bond strength of different adhesive systems to human dentin

• Main Authors: Renally Bezerra Wanderley Lima, Maria Luiza Pontual, Venâncio Fernandes Dantas, Sônia Saeger Meireles, Ana Karina Maciel Andrade, Rosângela Marques Duarte
• Format: Article
• Language: English
• Published: Universidade Estadual de Campinas 2019-12-01
• Series: Brazilian Journal of Oral Sciences
• Subjects: Dentin; Tensile strength; Radiotherapy; Head and neck neoplasms.
• Online Access: https://periodicos.sbu.unicamp.br/ojs/index.php/bjos/article/view/8657265

Aim: The aim of this study is to evaluate the effect of radiotherapy on the bond strength of resin-based composite restorations to dentin, performed either 24 h or 1 year before or after radiation. Methods: Ninety-six posterior teeth were randomly distributed into the following groups: IB (n = 16), irradiated teeth were restored 1 year after x-ray application; NB (n = 16), not irradiated teeth were stored for 1 year and then restored. IA (n = 32), teeth were restored and irradiated at 24 h or 1 year after the restoration. NA (n = 32), teeth were restored, not irradiated, and tested as IA. Eight samples from each group were randomly assigned to either the three-step or two-step etch-and rinse adhesive system procedure. The irradiated specimens were subjected to 60 Gy of x-ray radiation fractionally. The restored teeth were vertically sectioned, and 1-mm2 resin–dentin sticks were obtained and submitted to the microtensile bond strength test. The bond strength data were analyzed by two-way analysis of variance (ANOVA) followed by Tukey’s test (p < 0.05). Failure modes were examined by optical microscopy and scanning electron microscopy. Results: The IB group showed lower bond strength values compared to the NB group. The bond strength values between the adhesive systems were not statistically different. Conclusion: The application of radiation dose decreased the bond strength of the adhesive restorations to dentin when the bonding procedure was conducted 1 year after in vitro radiotherapy.