Fig. 3. Adhesion strength measured through peel-off test and SEM images after testing.

Adhesion strength of the HA-coated zirconia substrates with various sintering temperatures a. SEM images of the failure surfaces of the bare and HA-coated zirconia after the adhesion test: b bare zirconia, c HA600, d HA800, and e HA1000. The black and yellow dotted lines indicate the areas where the stud adheres to and epoxy remains, respectively. Scale bars: 500 nm