Dent Mater. 2026 Jan 19:S0109-5641(26)00015-1. doi: 10.1016/j.dental.2026.01.006. Online ahead of print.
ABSTRACT
OBJECTIVES: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.
METHODS: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett’s T3 post hoc test (α=0.05).
RESULTS: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.
SIGNIFICANCE: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.
PMID:41558951 | DOI:10.1016/j.dental.2026.01.006