Crowns fabricated at the dental lab or milled in-office are normally slightly tight and need to be adjusted for a perfect fit to ensure complete marginal seating. This is done intentionally-when the proximal contact is slightly tight, the crown can be adjusted, but contacts that are loose necessitate remaking the crown.
However, in my office, I have experienced that about 50% of crowns are too tight, and the Black Diamond Strips cannot get into the interproximal space to adjust the proximal contacts. Occasionally, the crowns are even too wide to fit into the space between two adjacent teeth, which can be very frustrating to dentists.
But here is the solution using the ContacEZ Black Diamond Strip:
Small spaces occur between natural teeth. Most of the authors recommend checking the proximal contact with dental floss, and floss does not properly detect these spaces.
-J.T. Lindquist 1951