BMC Oral Health, cilt.25, sa.1, 2025 (SCI-Expanded, Scopus)
Background: This study aimed to evaluate the repair bond strength of composite resin to two 3D-printed permanent resin materials using different universal adhesive systems—light-cure, self-cure, and dual-cure—following a standardized air abrasion. Methods: Seventy-two disc-shaped specimens (n = 12 per group) were fabricated using two different commercial 3D-printed materials: Saremco Crowntec and Bego VarseoSmile Crown Plus. After post-processing, all specimens were thermocycled for 5,000 cycles to simulate aging. The bonding surfaces were then subjected to air abrasion, followed by the application of one of three universal adhesive systems: light-cure (G-Premio Bond), self-cure (Tokuyama Universal Bond II), or dual-cure (Futurabond U). A composite resin (Filtek Z250) cylinder was then bonded and light-cured. Shear bond strength (SBS) was measured, and fracture modes were examined under a stereomicroscope. Data were analyzed using two-way analysis of variance (ANOVA) and Tukey HSD tests (p < 0.05). Results: Self-cure universal adhesives exhibited the highest SBS values, especially in the Bego material group (19.20 ± 2.11 MPa), while the lowest bond strength was observed in the Saremco + light-cure group (14.28 ± 1.23 MPa). Both the adhesive system (p < 0.001) and material type (p = 0.002) significantly affected SBS. Failure mode analysis revealed predominantly adhesive failures in the light-cure groups, and more mixed/cohesive failures in the self-cure and dual-cure groups. Conclusions: Bond strength of repaired 3D-printed permanent resins is significantly influenced by the adhesive systems and material type. Self-cure universal adhesives provided the most effective bonding performance, particularly when combined with Bego VarseoSmile Crown Plus.