National Dental Assisting Examining Board (NDAEB) Practice Exam

Which type of cement bonds directly with enamel, dentin, and metallic materials?

1. Zinc Phosphate

2. Resin-modified Glass Ionomer

3. Glass Ionomer

4. Polycarboxylate

The correct answer is: Glass Ionomer

The correct choice is Glass Ionomer cement, which has unique properties that allow it to bond effectively with enamel, dentin, and metallic materials. Glass Ionomer cement is made using a combination of fluoroaluminosilicate glass powder and polyacrylic acid, enabling it to adhere chemically to dental hard tissues and metals. This chemical bonding is significant because it provides a strong union between the cement and the tooth structure or restoration, leading to improved sealing and decreased risk of microleakage. The ability of Glass Ionomer to release fluoride as it sets also benefits the surrounding tooth structure by providing some level of protection against caries. While resin-modified Glass Ionomer and other types of cement may have advantages in specific scenarios, particularly in terms of aesthetics or certain physical properties, Glass Ionomer is particularly noted for its adhesive capabilities as a means of bonding directly with enamel and dentin. Zinc Phosphate cement, on the other hand, relies more on mechanical retention and does not bond as directly to these materials. Polycarboxylate cement can bond to enamel and dentin, but its bonding is not as strong or as directly effective as that of Glass Ionomer.