How to use a gingival retraction cord? Is it removed prior to impression taking or after?
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It's removed prior to taking the impression. The purpose of the retraction cord is to make the gingiva pull back from the tooth a bit so a good impression can be taken. If it's left in place while the impression is done, the impression will be inaccurate.
it is placed just below the gum line around the margin. it is taken out before final impression
My dentist puts the retraction cord in below the gum linr before the impression and takes it out after thr impression is taken.
The gigival retraction cord is placed in the sulcus (between the gum tissue and your tooth structure) to displace the gum tissue for a small period of time so that the impression that is taken for the crown or bridge can obtain the margin of the preparation so that the crown or bridge can fit your tooth structure flush without a void between the crown or bridge, This is called the margin. If the margin is not sealed properly you can end up with sensitivity or re-current decay.
It can be removed prior to the impression or after depending upon the dentists preference. Sometimes 2 are placed and one is removed prior to the impression and the other after.
After the bulk of tooth preparation is done for crown or bridge, the retraction cords (two) are placed. This helps to prepare the margins in a good visualized field. Here is the correct technique:
1. Place a thin (#0, 00 or 000) hemodent soaked (at least a minute)cord. This will protect the sulcus and prevent the violation of the biologic width.
2. Place 2nd (don't forget to soak in hemodent) cord (#1, 2 or 3 depending the thickness of gingiva) Do not push this cord down the sulcus and rather push the cord laterally to create a wider sulcus.Top part of this second cord should be above the gingival crest.
3. Let the cords stay for at least five minutes.
4. Using hemodent flush the 2nd cord and gently pull it out of the sulcus. At this point you should have a nice wide pocket where you can see the unprepared portion of your margin ( also called an emergence profile).
5. Leave the 1st (thin) cord in place. It will help to keep the pocket dry. Dry the pocket with air and apply your light body PVS.
Most of the time when you remove the impression the 1st cord will be removed attached to it.
The rest you know I think!
P.S. Marginate your provisional before taking your final impression.
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