TYPES:
Glass ionomer are classified into five types.
    1. Conventional glass ionomer cements.
    2. Resin modified glass ionomer cements.
    3. Hybrid ionomer cements. (Also known as dual cured glass ionomer cement).
    4. Tri-cure glass ionomer cements.
    5. Metal reinforced glass ionomer cements.

INDICATION:
    1. Type-2 glass ionomer for restorations.
    2. Type-3 glass ionomer for liners and bases.
    3. Type-4 glass ionomer for fissure sealants.
    4. Type-5 glass ionomer for core build up.
    5. Intermediate Restorations.
    6. Restorations for decidious teeth.
    7. Adhesive cavity liners(sandwich technique)

IMAGES:

Before

After

ADVANTAGE:

1. Inherent adhesion to tooth structure
2. High retention rate
3. Little shrinkage and good marginal seal
4. Fluoride release and caries inhibition
5. Biocompatible
6. Minimal cavity preparation

DISADVANTAGE:

1. Brittle
2. Soluble
3. Abrasive
4. Water sensitive during setting phase
5. Less aesthetic than composite

CONTRAINDICATION:

1. Aesthetic requirement
2. Area of high abrasion
3. Area of high occlusal load