Deep Margin Elevation (DME) is a restorative technique used when a cervical or proximal margin sits too far subgingivally for predictable isolation, matrix placement or bonding. The aim is simple: relocate that deep margin coronally with bonded restorative material so the definitive restoration can be completed under better access and isolation.
DME can be extremely useful, but the success of the technique depends on case selection, isolation, matrix adaptation and controlling the cervical seal. This guide covers the practical steps, the matrix and wedge options we use, and the common reasons DME becomes difficult.
What is Deep Margin Elevation?
Deep Margin Elevation involves placing a bonded restorative material at a deep cervical margin to bring the finishing line to a more accessible position. It is often used before direct or indirect restorative procedures when a proximal box extends subgingivally.
Clinically, this can make several later stages easier:
- rubber dam isolation;
- matrix placement and contour control;
- bonding and light curing;
- finishing and polishing;
- digital or conventional impression taking;
- cementation of an indirect restoration.
DME should not be viewed as a way to ignore poor access or uncontrolled bleeding. The deep margin still needs to be visible, clean and isolatable enough to bond predictably.
When might DME be useful?
Typical situations include:
- a deep proximal carious lesion extending below the gingival margin;
- replacement of a deep Class II restoration where the cervical box is difficult to isolate;
- preparation for an indirect onlay or overlay where one margin sits much deeper than the others;
- large posterior restorations where a deep margin makes adhesive procedures or cement clean-up difficult.
Case selection matters. If the margin cannot be isolated, the tissue cannot be controlled, or there is inadequate remaining tooth structure, DME may not be the appropriate solution.
Step 1: establish isolation and visibility
Before selecting a matrix, the deep margin needs to be visible and dry enough to work on. Rubber dam isolation is ideal where possible, but the exact clamp and dam setup will depend on the tooth and how apical the margin is.
Haemostasis and tissue control are equally important. A matrix placed into a bleeding sulcus will not create a predictable bonding environment.
If the cervical edge cannot be seen, it is usually too early to start placing restorative material.
Step 2: choose the right matrix strategy
The matrix is the most important mechanical part of a DME setup because it controls the new cervical contour and the seal at the deepest margin.
Circumferential matrix
For many DME cases, a circumferential matrix gives the most predictable stability because it wraps around the tooth and can be tightened apically.
Two useful options are the Premium Contra-Angle Tofflemire Retainer and the Nyström Universal Matrix Retainer.
The contra-angle Tofflemire can improve posterior access, while the Nyström retainer is particularly useful when you want a simple straight design with strong control over the band.
Sectional matrix
A sectional matrix can work for DME when the preparation still has enough anatomy to support the band and when a good cervical seal can be achieved with a wedge.
For routine cases, Classic Sectional Matrices are often adequate. When the proximal defect is wider, Double Curve Sectional Matrices can provide more built-in contour.
Saddle matrix
Saddle Matrices are useful when conventional ring placement is awkward, especially if there is no adjacent tooth or where the anatomy makes a standard sectional setup unstable.
Step 3: select the wedge carefully
The wedge should support the matrix at the cervical margin and help eliminate gaps. Bigger is not always better.
A wedge that is too small may leave a gap at the deep margin. One that is too large may distort the matrix or displace it coronally.
For difficult subgingival situations, Deep Margin Elevation Wedges can be particularly useful. These matrix–wedge hybrids are designed to seat deeply in the interproximal space and can simplify margin control in selected cases.
For more routine situations, transparent or wooden wedges may be sufficient. The important point is adaptation: the matrix should sit closely against the cervical tooth surface without rocking or distortion.
Step 4: verify the cervical seal before bonding
Do not assume the matrix is sealed simply because it looks stable from the occlusal view.
Before bonding:
- inspect the cervical margin directly if possible;
- check that the band is not lifted away from the tooth;
- confirm there is no obvious crevice where restorative material can extrude;
- adjust the wedge or matrix if the contour is being flattened or distorted.
This step prevents one of the most frustrating DME complications: finishing a restoration only to discover a cervical ledge or overhang.
Step 5: raise the margin conservatively
The aim is not to overbuild the entire proximal wall. DME is about relocating the deep cervical portion to a position where the remainder of the restoration can be completed more predictably.
Use a bonded restorative material appropriate for the case and place enough material to create a smooth, accessible new margin. Keep the new margin simple and finishable.
If the procedure is being used before an indirect restoration, the elevated margin should create a clean preparation outline that can be scanned, impressed and cemented without unnecessary subgingival complexity.
Step 6: finish and inspect the new margin
Once the material has been cured and the matrix removed, inspect the new margin carefully.
Check for:
- overhangs;
- voids;
- rough excess material;
- open cervical defects;
- poor emergence profile.
Finishing strips and fine burs can help refine interproximal and cervical contours. The surface should be smooth enough that the definitive restorative stage is not being built on top of a defective base.
Common DME problems
1. The matrix will not seal cervically
Try changing the wedge before changing the restorative material. A deeper or differently shaped wedge often improves matrix adaptation more effectively than simply tightening the retainer.
2. The band collapses into the preparation
A stiffer band or circumferential retainer may help. In some cases a 50 micron matrix is easier to control than a thinner band.
3. The margin remains contaminated
Stop and improve isolation. Continuing to bond onto a contaminated field defeats the purpose of DME.
4. The final contour is too bulky
Use the smallest amount of restorative material needed to relocate the margin. Overbuilding makes later preparation and cement clean-up more difficult.
Which matrix system would we choose?
- Relatively contained deep proximal box: sectional matrix + well-adapted wedge.
- Wide box: Double Curve matrix may provide better contour.
- No adjacent tooth or difficult ring placement: consider Saddle matrices.
- Very deep or unstable preparation: circumferential matrix with Tofflemire or Nyström retainer.
- Deep cervical margin requiring dedicated adaptation: consider DME Wedges.
Products commonly used for DME
Useful products in a DME setup include:
- Deep Margin Elevation Wedges
- Nyström Universal Matrix Retainer
- Premium Contra-Angle Tofflemire Retainer
- Classic Sectional Matrices
- Double Curve Sectional Matrices
- Saddle Matrices
You can browse the full matrix bands and retainers collection to compare the available systems.
Final thoughts
DME works best when it is treated as an isolation and matrix-management technique, not simply as “adding composite to a deep box”. The key questions are whether the margin can be isolated, whether the matrix is genuinely sealed, and whether the elevated margin will be easier to finish and restore than the original one.
When those conditions are met, DME can turn a difficult subgingival restorative situation into a much more controlled procedure.