On a patient with ideal tooth alignment, which embrasure will you attempt to place the wedge for a class II MO amalgam restoration?

In the context of a Class II MO (mesial-occlusal) amalgam restoration, the placement of a wedge is crucial for achieving proper contact and maintaining the integrity of the restoration. The ideal tooth alignment refers to a situation where teeth are positioned in a way that ensures optimal occlusion and spacing.

Placing the wedge in the lingual embrasure is correct because this is the location where it effectively helps to adapt the matrix band against the tooth structure, particularly in a Class II preparation. The main purpose of the wedge is to create a tight seal at the gingival margin and to ensure that the matrix band securely holds the shape of the restoration. When the matrix band is pushed against the tooth, the wedge is positioned to support the band in the lingual area where it is often necessary to improve the contact between the restoration and the adjacent tooth, thereby minimizing the risk of potential overhangs or gaps.

The lingual embrasure is typically more favorable in terms of access and visibility, allowing for better adaptation of the material. This is particularly important for achieving a smooth and durable final restoration. Therefore, placing the wedge in the lingual embrasure aids in achieving an effective and efficient sealing of the matrix during the restoration process.