Where should the restoration of a class II prep begin?

The correct answer is based on the principles of cavity preparation for a class II restoration. When restoring a class II cavity preparation, which typically involves the posterior teeth and affects the interproximal areas, beginning along the gingival floor is essential for several reasons.

Starting at the gingival floor ensures that you have an effective base to secure the restoration. It allows for proper adaptation of the restorative material to the tooth structure, providing an adequate seal and minimizing the risk of microleakage, which can lead to secondary caries. Additionally, addressing the gingival area first helps to ensure that the restoration contours can be appropriately sculpted to promote good contact with adjacent teeth, as well as proper occlusion.

In contrast, beginning the restoration from the occlusal surface may lead to insufficient attention to the gingival floor, while starting from the axial wall or proximal surfaces might compromise the integrity of the gingival seal. Prioritizing the gingival aspect can significantly enhance the overall success and longevity of a class II restoration.