Interdiffusion of a traditional glass ionomer cement into conditioned dentin

To investigate whether a new auto-curing glass ionomer cement (Fuji IX) in combination with polyacrylic acid (Cavity Conditioner) forms an interdiffusion zone both under laboratory and clinical conditions.

Seven vital human posterior teeth were selected. A flat dentin surface was created on the buccal surface in order to apply the glass ionomer material. Seven other extracted human molars were prepared following the same procedure as with the in vivo experimental teeth. After extraction of the in vivo restored teeth, the samples were cut and prepared for hybrid layer observation under scanning electron microscope.

An interdiffusion zone, of approximately 6 microns thick, was observed both under in vivo and in vitro conditions. At the interface between the two substrates, the interdiffusion zone was acid resistant and uniform.