SEM images of fracture modes of debonded One Up Bond F specimens (2,500×, Bar = 10 mm): (a) Control and fracture occurred at the bottom of the hybrid layer; (b) When blood contamination occurred and re-applied the adhesive (contamination 1), there was detrimental effect to the adhesion, as illustrated by cohesive failure of the adhesive; (c) When blood contamination occurred, then washed, dried and re-applied the adhesive (contamination 2), less infiltration of adhesive occurred.