Australian Dental Council (ADC) Test 2026 – 400 Free Practice Questions to Pass the Exam

The correct ranking of impression materials according to their flexibility from most to least flexible is based on their physical properties and how they behave when removed from the mouth.

Alginate is known for its high flexibility, which allows it to easily deform and return to its original shape without damage. This is particularly useful in dental impressions as it can accurately capture fine details of the oral structures while allowing for easy removal from undercuts.

Polysulphide materials possess a degree of flexibility, but it is less than that of alginate. They are more viscous and can be stiffer, especially when set. However, they still exhibit some flexibility which makes them suitable for certain types of impressions.

Silicone materials, while flexible, are typically less flexible than alginate and polysulphide but outperform some rigid materials. Certain types of silicone, particularly the addition-cured types, have some inherent rigidity, impacting their ability to adapt in certain scenarios.

Zinc oxide eugenol is the least flexible among these materials. It is known for its rigidity and dimensional stability upon setting. Once it hardens, it does not retain a level of flexibility, making it less ideal for situations requiring significant adaptation to the contours of the oral structures.

Thus, the ranking of