A good adhesive should possess all of the following EXCEPT:
Complete wetting occurs at a contact angle of 0° and no wetting occurs at an angle of 180°.
Thus, the smaller the contact angles between an adhesive and an adherend, the better the ability of the adhesive to flow into and fill in irregularities within the surface of the adherend. The fluidity of the adhesive influences the extent to which these voids or irregularities are filled.
Reference: PHILLIPS’ SCIENCE OF DENTAL MATERIALS, 12th ed page no 26
High adherend wetting
High contact angle
Low contact angle
High flow