<prompt> Which of the following etching pattern is optimal for bonding?Type 1Type IIType IIIType IV  <response>: Three types of etched patterns are noted. They are: Type I: Etched enamel surface in which the center of enamel rods is dissolved with periphery intact Type II: There is peripheral dissolution of enamel rods Type III: It is a combination of the above two patternsFor optimum bond strength, Type I pattern is preferred. 