For the research, it was selected first permanent molars (FPMs) with MIH from children aged 6-8 years. FPM fully erupted and with restorative treatment needed was the inclusion criteria. We excluded FPMs with destroyed crowns. The FPMs were randomly assigned to two groups: G1 (self-etching adhesive) and G2 (total-etching adhesive). Clinical evaluation was performed during 18 months according to the USPHS-Modified by a blinded examiner. The actuarial method was used to evaluate survival of the restorations and Fisher's exact test was used to compare differences between the groups (α=5%).