Impact of Different Photoinitiers of Adhesive Systems on Mechanical Properties, Sorption, Solubility, and Microtensile Bond Strength to Dentin

ABSTRACT Objective: To evaluate the influence of photoinitiators on the physicochemical properties of simplified conventional adhesive systems. Material and Methods: Three adhesive systems were tested: Adper Single Bond 2 (3M), Ambar (FGM), and Ambar APS (FGM). For the cohesive strength (CS) test, specimens (n =10) were prepared and subjected to mechanical testing in a universal testing machine (Instron 3342). For the cross-link density (CLD) test, eight specimens of each material were prepared and subjected to Knoop microhardness measurements before and after immersion in ethanol for 24 hours. For the sorption and solubility (SS) test, ten specimens (n=10) of each material were prepared and tested over 28 days. For the dentin bond strength (BS) test, human molars (n=6) were restored, sectioned, and tested in a universal testing machine at a 1 mm/min speed. The data were analyzed using one-way ANOVA, two-way repeated measures ANOVA, and Holm-Sidak for mean contrasts (α=0.05). Results: Statistical analysis revealed no significant differences between the materials in the BS (p=0.40), CS (p=0.356), CLD (p=0.189), and solubility (p=0.157) tests. However, for the sorption test, a significant difference was observed between the adhesive systems, with Single Bond showing the highest values compared to Ambar and Ambar APS, which were similar. Conclusion: The APS photoinitiation system provides no advantage in the analyzed properties.