Preliminary study on resin-dentin bond durability by alginate dialdehyde preconditioning

Abstract

Objective To investigate the effect of alginate dialdehyde (ADA) on demineralized dentin substrate, in its cross-linking degree, micromorphology, inhibition ability and resin-dentin bonding strength. Methods ADA was prepared, and analyzed by Fourier Transform infrared spectroscopy (FTIR) . Demineralized dentin powder were treated by 0.5%, 1%, 2%, 3%, 4% ADA for 1, 2, 30 min, respectively, and examined by Nihydri colorimetry for the cross-linking degrees, 5% Glutaraldehyde was used as positive control (1.0 ± 0.1) mm dentin discs were etched, rinsed and pretreated with ADA successively, and kept dry or moist for field emission scanning electron microscope (FESEM) . The inhibition of ADA on MMP-9 was analyzed by Sensolyte Generic MMP assay kit. Resin-dentin bonding specimens were prepared for micro-tensile bond strength evaluation (MTBS) , before and after thermolcycling. Data were analyzed by Multi-way ANOVA, Kruskal-Wallis test or One-way ANOVA by SPSS 22.0 software package. Results FTIR analysis confirmed the characteristic peak of aldehyde group in ADA. The cross-linking degree of ADA-treated DDP was exhibited concentration- and time-dependent and from which significant differences were found among different ADA concentration (F = 1329.423, P<0.001) and different time (F = 1142.93, P<0.001) . The FESEM result confirmed that the demineralized dentin collagen was in a homogenous and regular arrangement after ADA or GD treatment, except 0.5% ADA dry group. Over 93.5% of the MMP-9 was inhibited by 0.5% ~ 4% ADA (F = 13.786, P<0.001) . The 2% ADA group exhibited highest MTBS before [ (28.2 ± 4.2) MPa] (F = 5.544, P<0.001) and after [ (18.3 ± 3.7) MPa] (F = 5.181, P<0.001) thermolcycling. Conclusions 2% ADA could increase cross-linking degree of demineralized dentin substrate, keep collagen fiber from collapse, and inhibit the activity of MMP-9, thus increase the durability of the dentin adhensive. Key words: Alginates; Cross-linking reagents, natural; Resin-bonded, dentin; Alginate dialdehyde