One of the most important things we need to do to get a good impression is controlling tissue and getting hemostasis established. There are lots of ways that I like to do this. I have a diode laser which I like for when margins are sub gingival and tissue tends to want to fall over the edge of the margin so the machine can’t read it to the edge. Many people don’t have a diode so I recommend cord for those. I like a braided cord that won’t fall apart when I pull it from the sulcus.
The other issue most have is controlling the bleeding. I will tend to soak a cord in something without ferric sulfate. Aluminum chloride works well and will not stain the underside of the crown like ferric products. Viscostat Clear is a good product if you want to soak the cord or you can use the pastes like 3M Retraction Paste, Expasyl, Traxodent or other products. These products work very nice to control bleeding but not to move tissue out of the way. What to do in this situation?
The product that I want to recommend is Comprecaps from Coltene. They are anatomically designed and you can put them over the prep after you place your astringent of choice and have the pt close down on them. They will put pressure on the tissue and in combination with the hemostatic agents, will get tissue to stop bleeding and retract it. It is great to use after you are done prepping and imaging and are waiting for milling and characterization to be finished. Have the patient bite down on these and you will see no bleeding for the cementation process which is so important in getting a good bond!