Figure 5: Bond strengths of control (H1) and APC (H2*, H3**, H4***) brackets bonded to human teeth.

H2* APC bonded after 10 months shelf time using Transbond primer

H3** APC bonded after 2 months shelf time using Transbond primer

H4*** APC bonded after 2 months shelf time using Scotchbrand MP primer