**2.5 SEM evaluation**

To evaluate the surface (treated with Etching, Laser, and Laser + Etching) before bonding and the fractured surface between the composite resin and dentin side after measuring shear bond strength, the representative dentin specimens were selected randomly and mounted on aluminum stubs. The samples were then sputter-coated with gold palladium and examined by scanning electron microscopy (SEM) (ISI SX-30 Cambridge, MA, USA) with 1000X magnification.
