Have you ever over adjusted an interproximal contact of direct restorations? Unfortunately this happens to all of us on occasion and in most cases (unless you can add a contact in your office) it means that you must return the restoration(s) to the lab, which in turn means an extra appointment for you and your patient.
Even using the best labs, it's not uncommon to need to adjust these contacts on our indirect restorations. The difference is so small between a restoration with a light contact versus an ideal contact or a heavy contact. It's really remarkable that we ever get a restoration with perfect interproximal contact requiring no adjustments right out of the box.
One simple trick I've learned to make adjusting the contacts on my indirect restorations is to use a small piece of plastic based articulating film such as Accufilm. Just hold the piece of film between the contact you want to check, place the restoration(s), then give the film a slight tug. If the contact is too tight, the film will tear leaving a mark right where you need to adjust. Simply adjust the marked areas and repeat until the film pulls though with resistance (it will stretch a bit).John R. Carson, DDS, PC, Spear Visiting Faculty. [ www.johnrcarsondds.com ]