Which class of amalgam restoration utilizes a wedge?

A Class II amalgam restoration is designed for cavities that involve the proximal surfaces of posterior teeth, specifically addressing caries that occur in the areas between adjacent teeth. The use of a wedge is critical in this context for several reasons.

The wedge serves to help close the gap between the tooth and the matrix band, ensuring that the restoration is properly confined during the placement of the amalgam material. This leads to a more effective seal and helps prevent the ingress of bacteria and fluids, which is essential for the longevity and integrity of the restoration. Additionally, the wedge helps to achieve proper contour and allows for a tight interproximal contact, which is crucial in preventing food impaction and maintaining proper dental health.

In contrast, Class I restorations typically address the occlusal surfaces of posterior teeth and do not require the use of a wedge since they involve less complex interproximal relationships. Class III and Class IV restorations, which concern anterior teeth, usually do not utilize wedges as their preparation and restoration methods differ significantly from those needed in Class II restorations.