This clinical trial aims to evaluate if nano-hydroxyapatite (Nano-HA) toothpaste effectively treats children with Molar-Incisor Hypomineralization (MIH). It will also assess the safety of Nano-HA toothpaste. The main questions are:

• Does Nano-HA toothpaste reduce caries incidence, improve tooth aesthetics, and decrease hypersensitivity?
• How does Nano-HA compare to fluoridated toothpaste in terms of outcomes?

Participants will:

• Use Nano-HA or fluoridated toothpaste daily for 12 months.
• Visit the clinic for checkups and evaluations every 1 to 3 months.
• Record symptoms, brushing compliance, and sensitivity.

The study will compare Nano-HA toothpaste to fluoridated toothpaste to determine its efficacy in managing MIH .

Inclusion Criteria:

- Children aged 6-12 years.

• Diagnosed with Molar-Incisor Hypomineralization (MIH) in at least one first permanent molar or hypomineralization of a second primary molar (HSPM).
• Presence of white, creamy, yellow, or brown demarcated opacities
• Indexed teeth include permanent first molars and permanent maxillary incisors.

Exclusion Criteria:

• • Decayed permanent molars.

  • Diabetes, hypertension, sleeping disorders, or allergic reactions to medications.
  • Children on medication
  • Presence of other enamel defects (e.g., fluorosis, amelogenesis imperfecta, enamel hypoplasia, or white spot lesions).
  • Previous treatment with liquid enamel or other remineralizing agents on affected teeth.