Which material is known for high precision and is commonly used for occlusal bite records?

• A. Alginate
• B. Wax
• C. Polyvinyl siloxane
• D. Plaster

Answer: (C)

For accurate occlusal bite records, the material must reproduce fine details and stay dimensionally stable from seating to pouring the cast. Polyvinyl siloxane fits this need exceptionally well. It provides excellent detail reproduction and minimal dimensional change over time, so the recorded bite stays true even if you delay pouring the opposing model. It also has good elastic recovery and tear resistance, making removal from the mouth or a cast smooth without distortion. This combination of precision, stability, and ease of handling is why it’s the material most commonly used for bite registrations.

Alginate, while user-friendly, tends to change size with water loss or gain, leading to distortions—unreliable for precise occlusal records. Wax is susceptible to temperature and load-induced deformation, so it isn’t stable for accurate bite registration. Plaster can expand and is porous, introducing dimensional inaccuracies.