The spontaneous spreading of drops of polyisoprene melt terminated with methyl (PI-CH3) hydroxyl (PI-OH), and carboxyl groups (PI-COOH) oil hydrophilic silicon surfaces has been studied experimentally. Despite the fact that all three polymers have a similar surface tension (0.032 N/m) at the polymer-air interface, the equilibrium contact angles were 29 degrees, < 5 degrees, and 20 degrees, respectively. Spreading of PI-OH and Pl-COOH is slowed down as compared to PI-CH3, most probably due to the strong interfacial binding of the hydroxyl or carboxyl end group to the surface. We interpret and discuss the dynamic wetting, experiments using the hydrodynamic and molecular kinetic theory of wetting.