What do retraction cords do?

Gingival retraction : Gingival retraction cord moves the gum away from the tooth when a dental crown impression (or a bridge) is made.

Better impression!: Retraction cord is a string (often medicated with an astringent) temporarily placed below the gumline to allow the dentist to make a cleaner, more accurate impression. This allows the dental laboratory technician to make a better fitting crown or bridge. It is removed after the impression is made.

Retract and dry: Retraction cords are most often used when taking an impression for crowns or laminates.First, they help keep the gum tissue away from the tooth so that the impression material can more easily get into that crucial area under the gums. Secondly, they help keep the area dry. Both of these factors help produce a better, more accurate impression. They can also be used to retract the gums for fillings.

Push the gums away: Retraction cords are used to push the gums away from the tooth margin so that the dentist can make a mold of the tooth for a new cap.