Which type of glass ionomer cement is commonly used to cement orthodontic appliances?

Type II glass ionomer cement (GIC) is commonly used to cement orthodontic appliances due to its specific properties that make it suitable for this application. It is designed for use in areas requiring high strength and good adhesion, which are critical factors when bonding orthodontic brackets and other appliances to tooth surfaces.

Type II GIC has enhanced mechanical properties compared to other types, thanks to its formulation, which provides the necessary durability to withstand the forces experienced during orthodontic treatment. Additionally, it releases fluoride, which can help in the prevention of caries around the bonded areas, offering added protection for the teeth during orthodontic therapy.

In contrast, Type I GIC is typically used for liners and base materials, while Type III is generally intended for restorative applications where a thinner consistency and less strength are sufficient. Resin-modified glass ionomer cements, while versatile and fluoride-releasing, are often favored in situations requiring high aesthetics or for use in areas exposed to heavy occlusal forces, making them less common for initial orthodontic bonding compared to Type II GIC.