Objective: To evaluate the resin-dentin interfacial morphology and shear bond strength of several new dentin bonding systems on deep dentin of primary teeth after a 1-year storage period. Method and Materials: Test specimens were prepared using 5 adhesive systems ( Syntac Single-Component [ Ivoclar Vivadent], Prime & Bond NT [ Dentsply DeTrey], Adper Prompt L-Pop [ 3M ESPE], Gluma One Bond [ Heraeus Kulzer], and iBond [ Heraeus Kulzer]) on primary deep dentin. The shear bond strength data were evaluated with Kruskal-Wallis and Mann-Whitney U tests. Debonding surfaces were examined with stereo-microscope and scanning electron microscopy ( SEM). Results: The 1-day shear bond strength test values were, respectively, Adper Prompt L-Pop > iBond > Prime & Bond NT > Gluma One Bond > Syntac Single-Component, with the differences between Prompt L-Pop and Syntac ( U = 10, P =.006), Prompt L-Pop and Gluma ( U = 7, P =.002), and Adper Prompt L-Pop and iBond ( U = 16, P =.03) being statistically significant. The 365-day shear bond strength values were, respectively, Adper Prompt L-Pop > Prime & Bond NT > iBond > Syntac Single-Component > Gluma One Bond, with the differences between Adper Prompt L-Pop and Syntac ( U = 0, P =.000), Adper Prompt L-Pop and Gluma ( U = 1, P =.000), and Adper Prompt L-Pop and iBond ( U = 13, P =.01) being statistically significant. The differences between the 1-day and 365-day subgroup values of Syntac ( U = 18; P =.05) and Gluma ( U = 1, P =.000) were statistically significant. Almost all specimens showed adhesive failure at stereoptical examination ( P >.05), with the presence of resin remnants and tags on dentin and dentinlike remnants on resin surfaces at SEM. Conclusion: Syntac and Gluma group values decreased with aging. The best values were obtained with both Adper Prompt L-Pop groups.