What is essential to do before placing a matrix band for a posterior restoration?

Before placing a matrix band for a posterior restoration, isolating the tooth with a rubber dam is essential for several reasons. The rubber dam provides a clean and dry working area, preventing saliva and blood from contaminating the area where the restoration will take place. This isolation reduces the risk of infection and ensures optimal adhesion for the restorative material.

Using a rubber dam also enhances visibility and access to the tooth, which is particularly important for posterior teeth that are often located at the back of the mouth and can be challenging to work on without proper isolation. Additionally, it protects the patient's airway and prevents debris or materials from being inadvertently swallowed or aspirated during the procedure.

While verifying the size of the band, evaluating the occlusion, and ensuring proper lighting are all important considerations in the restorative process, they do not address the immediate need for a clean and dry environment as effectively as proper isolation does. Thus, isolating the tooth with a rubber dam is a critical step in the preparation for placing a matrix band for a posterior restoration.