Fahrzadeh, NihalTunca, Murat2025-05-102025-05-1020240889-54061097-675210.1016/j.ajodo.2023.09.0082-s2.0-85175243363https://doi.org/10.1016/j.ajodo.2023.09.008https://hdl.handle.net/20.500.14720/10925Tunca, Murat/0000-0002-9157-9390; Fahrzadeh, Nihal/0000-0003-2137-5453Introduction: We aimed to compare the shear bond strength (SBS) forces on the enamel surface with 2 adhesives after treatment with various radiation doses. Methods: A total of 120 premolars were included in the study. The teeth were randomly divided into 5 main groups (n = 24): negative control (without aging), positive control (with aging), 40 Gy, 60 Gy, and 70 Gy radiation. The 40 Gy, 60 Gy, and 70 Gy groups underwent conventional radiotherapy 5 days a week with a dose of 2 Gy each day. After the radiotherapy, all samples except the negative control group were subjected to thermal cycle aging. In all 5 groups, the specimens were divided into 2 subgroups, and half were bonded using 2 adhesives. After bonding, the universal Shimadzu test device was used to analyze the SBS. After the test, the tooth surfaces were examined under a stereomicroscope to determine the adhesive remnant index. Results: When adhesives were compared, Biofix adhesive's bond strength value was statistically higher in the 40 Gy group than in the Transbond XT group (P = 0.001). The SBS value was higher in all irradiated groups than in nonirradiated groups (P = 0.001). When the adhesive remnant index score was analyzed, no significant difference was found among the groups. Conclusions: The SBS increased in irradiated teeth compared with unirradiated teeth, and the SBS values of both adhesives were within the acceptable limits in all radiation groups. (Am J Orthod Dentofacial Orthop 2024;165:285-93)eninfo:eu-repo/semantics/closedAccessArticle1653Q2Q128529337897485WOS:001194002100001