National Dental Assisting Examining Board (NDAEB) Practice Exam

What is the usual material of choice for Class III and Class IV restorations?

1. Gold

2. Composite Resin

3. Glass ionomer

4. Amalgam

The correct answer is: Composite Resin

Composite resin is the material of choice for Class III and Class IV restorations due to its aesthetic properties and ability to bond to tooth structure. Class III restorations involve areas on the anterior teeth that do not include the incisal edge, while Class IV restorations encompass areas that do include the incisal edge. Since these restorations are typically made on visible front teeth, the color-matching capability of composite resin allows for a more natural appearance, blending seamlessly with the existing tooth structure. Additionally, composite resins have improved strength and wear resistance, which makes them suitable for areas that endure stress, such as the biting surfaces, especially when they involve incisal edges in Class IV restorations. Adhesive dentistry techniques allow for better retention of these materials to the tooth structure compared to traditional materials, providing longevity and reducing the likelihood of micro-leakage or further decay. In contrast, materials like gold and amalgam, while durable and suitable for posterior restorations, are less aesthetic for anterior work. Glass ionomer, while useful in certain scenarios for its fluoride-releasing properties and ease of placement, may not provide the same degree of aesthetic integration and wear resistance required for these specific restoration types.