- Expasyl is a popular gingival retraction material widely used in dental procedures to achieve effective gingival displacement.
- It is composed primarily of kaolin, an inorganic clay that acts as an absorbent and provides bulk, combined with aluminum chloride, which serves as a hemostatic agent to control bleeding and reduce gingival inflammation.
- This combination allows Expasyl to provide gentle but effective retraction without causing significant trauma to the gingival tissues.

- Other options mentioned, such as Hemodent and ViscoStat, contain different hemostatic agents like ferrous sulfate or ferric sulfate and are typically used as gingival retraction solutions rather than paste materials like Expasyl.
- Additionally, Retraction cord with ferric sulfate refers to a physical cord impregnated with ferric sulfate and is not composed of kaolin and aluminum chloride.

Thus, the distinguishing feature of Expasyl is its paste consistency and unique composition of kaolin and aluminum chloride, differentiating it from other retraction agents.

Reference: Textbook of Prosthodontics, Volume 1, Chapter 6: Gingival Retraction Techniques, Page 85