A Class II cavity requires which of the following?

A Class II cavity refers to a dental carious lesion that affects the proximal surfaces of posterior teeth, specifically molars and premolars. When it comes to restoring a Class II cavity, the use of a Tofflemire retainer, which holds matrix bands in place, is essential. This device helps create a temporary wall around the tooth and establishes a proper contact point with the adjacent teeth, allowing for an effective restoration.

The use of a rubber dam, while it can be helpful for moisture control during the procedure, is not always a strict requirement for every dentist when treating a Class II cavity. Similarly, while filling material is indeed necessary for the restoration itself, the question specifically addresses the requirements for the procedure, which includes the proper placement and shaping of the restoration. A dental crown may be needed in more severe cases of decay, but it is not the direct requirement for a Class II restoration unless the tooth structure is significantly compromised. Therefore, the Tofflemire retainer is the most relevant tool for the appropriate procedure of restoring a Class II cavity, making it the correct answer.