Where should the mesial proximal margin for partial coverage restorations be placed?

The mesial proximal margin for partial coverage restorations should be placed just buccal to the proximal contact area. This positioning is crucial for several reasons. First, placing the margin just buccal to the contact area allows for optimal retention and resistance form of the restoration. It enables the restoration to be more securely anchored, minimizing the risk of dislodgement.

This position also facilitates the proper adaptation of the restoration to the tooth structure, ensuring that it meets the requirements for biofunctionality and aesthetic outcomes. Additionally, when the margin is appropriately placed, it helps maintain the integrity of the gingival tissues, reducing the likelihood of irritation or periodontal issues.

In contrast, placing the margin too far buccally would compromise the fit and function of the restoration, and positioning it just lingual to the proximal contact area could lead to challenges in achieving a proper seal, which is essential for preventing bacterial ingress under the restoration. Aligning the margin with the occlusal surface may not provide the best biomechanical support for stresses that the restoration will endure. Thus, the optimal placement just buccal to the proximal contact area is both clinically relevant and advantageous for successful outcomes in partial coverage restorations.