Effect of zinc nanoparticles on the mechanical properties and stability of the resin-dentin bonded interface

• Published in: Journal of adhesion science and technology 2024-07, Vol.38 (14), p.2517-2532
• Main Authors: Santi, Marina Rodrigues, Sahadi, Beatriz Ometto, Soto-Montero, Jorge Rodrigo, Lins, Rodrigo Barros Esteves, Giacomini, Marina Ciccone, Wang, Linda, De Souza, Grace Mendonça, Martins, Luís Roberto Marcondes
• Format: Article
• Language: English
• Subjects: adhesion; bond strength; Bonding strength; Chlorhexidine; Dentin; Failure modes; Fluorides; Interface stability; Mechanical properties; Modulus of elasticity; Morphology; Nanohardness; Nanoparticles; Phosphoric acid; Pretreatment; remineralization; Resins; Variance analysis; zinc fluoride; Zinc fluorides; Zinc oxide; Zinc oxides
• ISSN: 0169-4243; 1568-5616
• DOI: 10.1080/01694243.2024.2304965

To evaluate the effect of zinc oxide and zinc fluoride nanoparticle solution (ZNS) as pretreatment on the mechanical properties and stability of resin-dentin bonded interface. Pretreatment solutions were applied after phosphoric acid: 5 and 10% Zinc Oxide (ZO5; ZO10); 1.5 and 3% Zinc Fluoride (ZF1.5 and ZF3); 0.2% chlorhexidine (CHX-positive control) and no pretreatment (NC-negative control). The treated teeth were restored and stored for 24 h and 12 m prior to microtensile bond strength (µTBS) testing (n = 8). Failure mode, nanohardness (NH) and young's modulus (YM) (n = 3) were also evaluated. In situ zymography (n = 3) and interface morphology (n = 3) were evaluated after 24 h. The antibacterial activity was determined by minimum inhibitory (MIC) and bacterial (MBC) concentration. The µTBS was evaluated by two-way mixed ANOVA and NH and YM data were analyzed by two-way mixed repeated-measures ANOVA (α = 0.05). In situ zymography, interface morphology, MIC and MBC were descriptively analyzed. The µTBS of ZF3, ZO10 and CHX was maintained over time, while for ZF1.5 and Z05 it was increased. Mixed failures were the most prevalent for all groups. ZF3 presented higher values of NH and YM with incorporation of nanoparticles being observed within the hybrid layer on the interface morphology image. CHX presented the lowest enzymatic activity followed by ZO5. MIC and MBC for ZO were 62.5 µg/mL and ZF 3.25 µg/mL, respectively. Pretreatment with ZNS, specially zinc fluoride, seems to be a promising method to increase the longevity of restorations.