Effects of a modified cold atmospheric plasma jet treatment on resin-dentin bonding.

The radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma is a novel cold atmospheric plasma (CAP) source, which has low energy characteristic. This study investigated the effect of RF-APGD plasma on the mechanical properties of dentin collagen and resin-dentin bonding. The scanning electron microscopy analysis was performed before and after a novel RF-APGD plasma and a conventional CAP treatment and a tensile test was carried out for the stiffness of dentin collagen. The microtensile resin-dentin bond strength was tested either immediately or after a 50,000-cycle thermocycling process. Dentin collagen maintained an intact structure after a 45-s RF-APGD plasma treatment, whereas even a 10-s treatment with the conventional CAP collapsed the collagen scaffold. When compared with control groups, the RF-APGD plasma treatment showed: (i) an improved stiffness of dentin collagen; (ii) a significant improvement in the bonding strength before/after artificial aging. Thus, RF-APGD plasma treatment has excellent prospects as a resin-dentin bonding protocol.