Capturing an accurate dental impression with crisp margins can be a highly technical process. This is especially true when the margins are placed subgingivally. Gingival retraction pastes and gels can be used to create space between the prepared tooth and the sulcus. These materials are expressed around the preparation, often directly into the sulcus and their astringent properties keep the area free of moisture so the impression material can be placed immediately after the retraction material is removed. Some retraction pastes and gels can be used in conjunction with retraction cord, while others work on their own.