DANB General Chairside Practice Test

In the use of a universal matrix band and retainer, what is a true statement regarding their placement?

1. The matrix retainer is placed on the facial surface, and the wedge is placed from the buccal

2. The matrix retainer is placed on the lingual surface, and the wedge is placed from the proximal

3. The matrix retainer is placed on the buccal surface, and the wedge is placed from the lingual

4. The matrix retainer is placed on the occlusal surface, and the wedge is placed from the apical

The correct answer is: The matrix retainer is placed on the buccal surface, and the wedge is placed from the lingual

The choice that states the matrix retainer is placed on the buccal surface, and the wedge is placed from the lingual is correct because it accurately describes the proper placement technique for a universal matrix band and retainer in operative dentistry. When using a universal matrix band, it is important to position the matrix retainer on the buccal aspect of the tooth being prepared. This placement allows for effective contouring of the restoration and proper adaptation to the tooth structure to prevent any gaps that might lead to improper sealing or esthetic issues. The wedge, on the other hand, is inserted from the lingual side. This approach is essential as it helps to ensure that the matrix band is pushed against the proximal surfaces of the adjacent teeth, providing a tight contact point which is crucial for creating a proper seal and achieving the desired interproximal contacts in the final restoration. This technique also minimizes the risk of the matrix band becoming dislodged during the restoration process and facilitates adequate access for the dentist to carry out the filling. While other options present various incorrect placements or orientations of the matrix retainer and wedge, they do not align with the established best practices in dental procedures.