When taking a dental impression, obtaining proper retraction is an important part of accurately capturing the preparation margins. The use of gingival retraction cord or gingival retraction caps can make this process easier and lead to better impression results. Retraction cord is made from braided, twisted or knotted threads that are available in different thicknesses. These cords can be treated with astringent and hemostatic agents to help provide retraction that lasts while the impression is taken. Retraction caps are placed over the prepared tooth and when the patient bites down, they push a retraction material into the sulcus to create the retraction needed for the dental impression.