In dental impression making, what effect can the presence of oil or water cause?

• A. Improved clarity
• B. Increased distortion
• C. Decreased quality
• D. No significant effect

Answer: (C)

The presence of oil or water during the dental impression making process can lead to decreased quality of the impression. Both oil and water can create a barrier between the impression material and the surface being captured, resulting in surface irregularities, poor detail reproduction, and inconsistent material set. When an impression is compromised by contamination, it can become difficult to ensure an accurate fit for crowns, bridges, or other dental restorations.

In contrast, improved clarity and decreased distortion would typically result from a clean and properly prepared surface, suggesting that environmental factors like oil and water can introduce complications. The response of impression materials to unintended substances highlights the importance of maintaining a clean working environment to produce high-quality dental impressions.