In dental school we were indoctrinated with an absolute fact: Interproximal enamel is very sacred and should not be touched. However, interproximal enamel is no different than any other enamel. Once you get over the unfamiliarity of exposing the contact, you realize that you are over thinking it. Simply burnish the matrix against the contiguous tooth and an outline of the adjacent contact becomes apparent. Make your opening within the confines of the outline, it doesn’t have to be exact.
The bond through the opening is small and to a smooth surface. It will break cleanly.
Advantages are:
1) Restoring the tooth in a neutral position. No need to wedge and force teeth apart. The wedge gets in the way of creating a rounded emergence contour.
2) Superior isolation and visibility.
3) Tight contacts assured, including MOD’s.
4) For Class III and Class IV’s contour is burnished into the matrix resulting in a firm rounded surface for condensing composite. (Mylar strips and wedges create flat emergence contours and black triangles.