Sukprasert N.Harnirattisai C.Senawongse P.Sano H.Saikaew P.Mahidol University2023-06-182023-06-182022-11-01Clinical Oral Investigations Vol.26 No.11 (2022) , 6743-675214326981https://repository.li.mahidol.ac.th/handle/20.500.14594/84424Objective: To evaluate the effect of a time delay before the light activation of resin composite on the microtensile bond strength (µTBS) of self-etch adhesives under dynamic simulated pulpal pressure. Materials and methods: One hundred twenty crown segments were prepared from human third molars. Dentin surfaces were prepared with coarse diamond burs and connected to a dynamic pulpal pressure device. The self-etch adhesives used were Clearfil SE Bond (CSE), G2-Bond Universal (G2B), Clearfil Universal Bond Quick (CBQ), and G-Premio Bond (GPB). Each adhesive was divided into 3 subgroups: immediate light activation of resin composite (T0), delayed light activation for 150 s (T1), and 300 s (T2). The µTBS data were obtained after 24-h water storage. Scanning electron microscopy was used to evaluate the nanoleakage at the resin–dentin surface. The µTBS data were analyzed using two-way ANOVA and Duncan’s multiple comparisons. Results: All adhesives demonstrated a significant reduction in µTBS at T2, except for CBQ where the bond strength was not affected by the delayed light activation times. The two-step self-etch adhesives (CSE and G2B) demonstrated higher bond strength than the one-step adhesives at all conditions. Nanoleakage was observed in all adhesives at T2; however, nanoleakage was detected only in CBQ and GPB at T1. Conclusions: Delayed light activation of resin composite adversely affected the dentin bond strength of self-etch adhesives. Two-step self-etch adhesives had better bonding performance than one-step self-etch adhesives. Clinical relevance: After adhesive application, resin composite should be adapted and cured as soon as possible.DentistryArticleSCOPUS10.1007/s00784-022-04634-32-s2.0-851347480821436377135876892