Microtensile bond strength of bioactive restorative materials to sound and caries-affected primary dentin

Sažetak

Background: The structure of primary caries-affected dentin may influence adhesion and clinical outcomes of restorative materials. This study evaluated the microtensile bond strength (µTBS) of six bioactive restorative materials to sound (SD) and caries-affected (CAD) primary dentin. Materials and Methods: Occlusal cavities were prepared in 84 extracted primary molars which were randomly assigned into SD and CAD groups (n=42). Artificial CAD was created using a demineralizing solution. Each group was subdivided into six subgroups (n=7) restored with bioactive composite (Activa BioActive Restorative), self-cure composite (Stela), alkasite (Cention Forte), giomer (Beautifil Bulk), glass hybrid cement (Equia Forte HT), and nanohybrid composite (Tetric PowerFill). To simulate aging, samples underwent thermocycling for a total of 10,000 cycles. Stick-shaped specimens (~1 mm²) underwent µTBS testing at 0.5 mm/min. Failure pattern analysis was assessed under a stereomicroscope. Results: Significant differences among the materials were observed in both SD and CAD groups (one-way ANOVA, p < 0.001). Self-cure composite and alkasite did not show differences in µTBS when SD and CAD were compared. All materials showed predominantly adhesive mode of failure. Conclusion: µTBS of bioactive restorative materials to primary dentin is influenced both by the material type and dentin substrate.