Figure 2. Bond strength of resin to etched dentin primed by HEMA solutions with various pH values of the aqueous solution for the HEMA primer. Error bar shows SD. Dashed line represents the bond strength when Clearfil New Bond was applied to etched dentin without any primer pre-treatment. Solid line represents the bond strength when the dentin was conditioned with Clearfil SE Bond primer instead of 40% phosphoric acid.