Rank the following impression materials according to their flexibility.

The ranking of impression materials based on flexibility is integral for understanding their application in dental procedures. The correct order indicates that alginate is the most flexible material, followed by polysulphide, silicone, and zinc oxide eugenol, which is the least flexible.

Alginate is known for its ability to easily conform to the contours of the oral cavity, making it highly flexible and effective for creating accurate impressions of soft tissue and teeth. Its hydrocolloid nature allows it to exhibit good elasticity, aiding in its removal even from undercuts without distorting the impression.

Polysulphide, while not as flexible as alginate, still possesses significant elasticity, which allows it to capture fine details of the oral structures. Its flexibility is adequate for making functional impressions and for cases where slight deformation is acceptable.

Silicone materials generally provide good flexibility, but they are often stiffer compared to alginate and polysulphide. Certain types of silicone can offer high detail reproduction but tend to have limitations in flexibility compared to the aforementioned materials.

Zinc oxide eugenol is the least flexible impression material among the options listed. It is primarily used for specific cases and is rigid, making it unsuitable for areas of the mouth requiring high adaptability. This lack of