Etch-bleach-seal Technique in Managing Opacities Related MIH Using Icon®

In the test group, the investigators will be applied sodium hypochlorite 5.25% by using cotton wad on the opacity before treatment, then after the first and second etching cycles (application of the Icon-Etch (ICON® -Etch; DMG, Hamburg, Germany) and Icon-dry (ICON® -Dry; DMG, Hamburg, Germany) according to the manufacturer's recommendations) as irrigation step and following the third -Etch etching cycle Icon-infiltrant (ICON® -Infiltrant; DMG, Hamburg, Germany) will be applied.

In control group, the investigators will be applied the same protocol of test group but without using sodium hypochlorite