Evaluating mesoporous zinc oxide nanoparticles for dentin pretreatment: Synthesis, characterization, and bond...

This study aimed to synthesize mesoporous zinc oxide nanoparticles (ZnO NPs) and evaluate their effect as dentin pretreatments on the microshear bond strength (μSBS) of a universal adhesive.

This in vitro experimental study used 100 extracted human molars sectioned to expose mid-coronal dentin. Samples were divided into five groups (n = 20) based on pretreatment: no treatment, chlorhexidine (CHX), calcined mesoporous ZnO NPs, noncalcined mesoporous ZnO NPs, and ZnO NPs. Each group was subdivided into two subgroups (n = 10) based on the universal adhesive application mode: etch-and-rinse (E and R) or self-etch (SE). Pretreatments were applied for 1 min. Composite resin was bonded using a universal adhesive. After 24 h of storage in distilled water at 37°C, μSBS testing was performed. Statistical analysis included the Shapiro-Wilk test for normality, two-way analysis of variance with Tukey's post hoc test, and t-tests, with significance set at P < 0.05.

The noncalcined mesoporous ZnO NP group showed the highest μSBS, followed by the ZnO NP group, with significant differences compared to other groups (P < 0.05). Lower μSBS values were observed in the calcined mesoporous ZnO NP, CHX, and untreated groups. The adhesive application mode had a significant effect only in the untreated and calcined mesoporous ZnO NP groups (P < 0.05), with SE yielding higher μSBS than E and R.

Noncalcined mesoporous ZnO NPs enhanced dentin bond strength more effectively than other pretreatments, including CHX, indicating their potential as a promising alternative in adhesive dentistry.