Dentin biomodification with collagen crosslinkers has been shown to reduce the endogenous enzymatic degradation at the resin-dentin interface. The aim of this study was to evaluate the effect of six collagen crosslinkers on the immediate and one-year micro push-out (µPO) bond strength to dentin.
Method:
Eighty-eight molars were divided into 11 groups. Cavities (diameter:1.8 mm, depth: 2 mm) were prepared on superficial dentin surface after removal of occlusal enamel. After 37 % phosphoric acid-etching (15 s), cavities were treated for 1 min with 1) glutaraldehyde 1% (GA), 2) GA 5%, 3) grape-seed extract (GS) 1%, 4) GS 5%, 5) sumac (S) 10%, 6) curcumin (CR) 20µM, 7) CR, 200µM, 8) riboflavin/UV (R) 0.l%, 9) R, 0.5%, 10) riboflavin-5-phosphate/UV (RP) 0.1% before application of the adhesive (Adper Scotchbond Multi-Purpose, 3M ESPE). No treatment group served as control (n=16/per group). Cavities were restored with resin composite (Filtek Supreme XTE, 3M ESPE) and light-cured for 40 s. After storage at 37 °C for 24h, 2mm-thick dentin disks were cut parallel to occlusal surface. Each group was divided into two subgroups for immediate and 1-year µPO testing. The long-term samples were incubated at 37°C in artificial saliva. Specimens were subjected to µPO test at crosshead speed of 1mm/min at a universal testing machine. Data were statistically analyzed using Two-way ANOVA and posthoc tests (Tukey’s, α=0.05).
Result:
The immediate mean of µPO (mean±std) ranged between 57.5±10 and 72.9±16 MPa for GSI and S respectively. No significant difference was found between the control and crosslinker groups (p>0.05). After one-year storage, control group showed 30% reduction in bond strength, which was significantly different than the crosslinker groups (p<0.05).
Conclusion:
The pretreatment of dentin surface with collagen crosslinkers showed no reduction on immediate bond strength, and preserved the bond strength after one-year storage in artificial saliva.