Benefits of Deep Margin Elevation for Treating Subgingival Margins

Subgingival margins present as a common clinical challenge. In cases where subgingival margins are present, deep margin elevation can be a useful technique to help restore teeth to the proper form and function.

What is deep margin elevation? In essence, this procedure involves placing a material to raise the restorative margin to an equigingival or supragingival location. Some of the earliest work published on the concept came from Dietschi and Speafico in 1998.

This technique has been referred to by many different names, including the “open sandwich technique,” “proximal box elevation” and “margin elevation technique.” The concept gained traction in 2012 when Pascal Magne discussed the concept as a paradigm shift for direct and indirect restorations.

Since Magne re-introduced the concept, deep margin elevation has been gaining popularity as a way to raise indirect restoration margins supragingivally, especially for intraoral scanning. Margin elevation can be performed using a host of different materials, such as composites, glass ionomers or resin-modified glass ionomers.

How does deep margin elevation work? Once the subgingival aspect of the prep is completed, a matrix is placed and tightly adapted to the tooth structure. In most cases, a wedge is not placed, enabling the margin elevation to reproduce an appropriate emergence profile.

The tooth is treated using the etching and bonding protocol of your choice (for composite) or a tooth conditioner (for glass ionomer or RMGI). The material is allowed to flow passively against the matrix until it is at an equigingival or supragingival location.

Typically, a post-op bitewing is taken to confirm the proper adaptation of restorative material to tooth structure, especially when deep margin elevation is being used to elevate a margin for indirect restorations. When performed in a limited area, deep margin elevation can be utilized in close proximity to the bone with negligible effects on the biologic width.

In some cases, the matrix band may need to be adapted in order to accommodate the subgingival aspect of the prep. Either a #2 Tofflemire band or a modified #1 Tofflemire band can be used to extend the matrix to ensure an adequate seal of the margin elevation material to the tooth.

Deep margin elevation has been shown to provide predictable long-term survival rates up to a decade after being performed².  It’s yet another tool in our toolbox that can be used to manage subgingival preparations.

References

1. Dietschi, D. and Spreafico, R..  “Current clinical concepts for adhesive cementation of tooth-colored posterior restoration.”  Prac Periodont Aesthet Dent 1998; 10(1): 47-54