Riboflavin/UVA photo crosslinking versus conventional dentin biomodifiers: Comparative evaluation of shear bond strength and resin tag formation in artificially demineralized dentin

AIM: generation adhesive bonded to artificially demineralized dentin in comparison to the control. MATERIAL AND METHOD: Seventy-five non-carious permanent premolars were used in this study. Dentin was exposed to the middle third level, followed by artificial caries induction using the pH-cycling method. The samples were etched using phosphoric acid (PA). The samples were randomly assigned to five groups based on the type of dentin biomodification. Group 1 (No dentin biomodification); Group 2 (GSE); Group 3 (CPP-ACP); Group 4 (RF/UVA); and Group 5 (HANPs). After modification, a fifth-generation adhesive was applied to the prepared dentin surfaces, which were then restored with composite resin. To simulate aging, all samples were subjected to thermocycling for 10,000 cycles. SBS and failure mode assessments were performed on each cohort using a universal testing machine and stereomicroscope, respectively. Scanning electron microscopy (SEM) was used to determine the length of the resin tags. Comparisons among different groups were performed using one-way ANOVA and Tukey's post-hoc tests (p<0.05). RESULT: The maximum resin tag length (135.43±5.19 μm) and SBS (11.43±0.77 MPa) were observed in Group 2 (GSE). The minimum RTL (53.11±1.12 μm) and SBS (6.21±0.39 MPa) were observed in Group 4 (RF/UVA) CONCLUSION: GSE and CPP-ACP, as dentin biomodifiers, appear to be promising approaches for improving RTL and SBS of 5th-generation adhesives on artificially demineralized dentin. In contrast, RF/UVA and HANPs significantly compromised adhesive penetration and SBS compared with the untreated control, underscoring the mechanism-specific and material-dependent nature of dentin biomodification strategies.