Inclusion Criteria:  Healthy children, aged 6-12 years, who attended the pediatric dentistry clinic regular dental examination Cooperative children diagnosed with MIH according to European Academy of Paediatric Dentistry (EAPD) criteria Presenting at least two FPMs that were fully erupted and indicated for non-invasive fissure sealant. The FPMs with white, yellow or brown lesions, indicating mechanical and chemical alteration of the enamel and increased caries risk  Exclusion Criteria:  Children having hypomineralized FPMs with post-eruptive breakdown, cavitated carious lesions, restorations or fixed orthodontic appliances Enamel defect due to a condition other than MIH