Water powder ratio of dental stone and plaster is respectively
**Core Concept**
Dental stone and plaster are types of dental impression materials used in dentistry. The water powder ratio (W/P ratio) refers to the specific proportion of water to powder required for optimal mix and set of the material.
**Why the Correct Answer is Right**
The correct W/P ratio is essential for achieving the desired properties of the dental stone or plaster, such as setting time, strength, and dimensional accuracy. Dental stone typically requires a lower W/P ratio (around 0.2-0.3 mL/g) to produce a harder and more durable material, while dental plaster requires a higher W/P ratio (around 0.5-0.6 mL/g) to produce a softer and more flexible material.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not provide a specific W/P ratio for dental stone or plaster.
* **Option B:** This option is incorrect because it suggests a higher W/P ratio for dental stone, which would result in a weaker and more porous material.
* **Option C:** This option is incorrect because it suggests a lower W/P ratio for dental plaster, which would result in a material that is too hard and brittle.
**Clinical Pearl / High-Yield Fact**
When working with dental stone or plaster, it is essential to follow the manufacturer's recommended W/P ratio to achieve the desired properties and prevent errors in impression taking or casting.
**Correct Answer: C. 0.5-0.6 mL/g**