## **Core Concept**
The question tests the understanding of the effects of heat on denture materials, specifically focusing on the properties of acrylic resin, a common material used in denture fabrication.

## **Why the Correct Answer is Right**
Dentures made from acrylic resin can deform or change shape when exposed to high temperatures, such as boiling water. This is because acrylic resin has a relatively low heat deflection temperature, meaning it can soften and lose its shape when heated above a certain threshold. Boiling water, at 100°C (212°F), can easily exceed this threshold, leading to distortion of the denture.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because cleaning dentures in boiling water does have a specific effect, which is distortion or deformation due to the reasons mentioned above.
- **Option B:** This option is incorrect as it does not accurately describe the effect of boiling water on dentures made of acrylic resin.
- **Option C:** While some denture materials or parts (like metal parts) might not be affected by boiling water in terms of deformation, the primary concern with boiling water and dentures is the effect on acrylic resin parts.
- **Option D:** This option is incorrect because it implies no effect or an unspecified effect, whereas boiling water can indeed cause deformation.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that dentures should be cleaned with mild soap and lukewarm water to prevent damage. Ultrasonic cleaners or specific denture cleaning solutions are often recommended as they effectively clean without causing damage.

## **Correct Answer:** .