Incorporation of ZnCl2 into an etch-and-rinse adhesive system on flexural strength, degree of conversion and bond durability to caries-affected dentin.

Purpose: To evaluate the effect of a zinc chloride (ZnCl2) solution (2% wt), incorporated into a two-step etch-and-rinse adhesive system (AS), on microtensile bond strength (µTBS) to caries-affected dentin (CAD).

Methods: First, the degree of conversion (DC) of the AS with and without the ZnCl2 solution was evaluated by Fourier transform infrared spectroscopy (FTIR). Second, beam-shaped samples (7 mm × 2 mm × 1 mm) were prepared with the AS containing the ZnCl2 solution to perform flexural strength (FS) tests.