Which of the following materials is often used as a base layer in the sandwich technique?

The use of glass ionomer as a base layer in the sandwich technique is grounded in its unique properties, which make it particularly suitable for this purpose. Glass ionomer cement bonds well to both the tooth structure and the restorative material, providing a secure interface that can enhance the overall longevity of the restoration.

Additionally, glass ionomer releases fluoride, which can contribute to remineralization of the tooth structure and help in preventing future caries. This is especially valuable in areas where the underlying dentin may be at risk or in patients who are susceptible to decay.

In the sandwich technique, a glass ionomer base is placed beneath a composite or another restorative material. This layering approach takes advantage of the strengths of each material; the glass ionomer provides a strong foundation and the composite offers aesthetic qualities and durability on top.

Other materials such as composite, silicate cement, and resin might not offer the same benefits in terms of adhesion or fluoridation, thus making glass ionomer the ideal choice for this technique. This is crucial for maintaining tooth health and ensuring efficacy in dental restorations.