Which material is commonly used for bite registration due to good dimensional stability and accuracy?

Which material is commonly used for bite registration due to good dimensional stability and accuracy?

• A. Alginate
• B. Wax
• C. Polyvinyl siloxane
• D. Zinc oxide-eugenol paste

Answer: (C)

The key idea is that bite registration material must hold its shape precisely after the bite is captured, so the occlusion recorded matches the finished models. Polyvinyl siloxane, an addition silicone, provides superior dimensional stability and high accuracy. It shows minimal polymerization shrinkage and very little dimensional change over time, even if the registered bite sits for a while before pouring the cast. It also has good elastic recovery, so it resists distortion when the registration is removed from the teeth and then later used to mount the models. This combination makes it the most reliable choice for precise bite registrations. Alginate tends to undergo dimensional changes with water loss or uptake, leading to distortion. Wax readily distorts with temperature changes and handling. Zinc oxide–eugenol paste can creep and deform over time, reducing accuracy.

The key idea is that bite registration material must hold its shape precisely after the bite is captured, so the occlusion recorded matches the finished models. Polyvinyl siloxane, an addition silicone, provides superior dimensional stability and high accuracy. It shows minimal polymerization shrinkage and very little dimensional change over time, even if the registered bite sits for a while before pouring the cast. It also has good elastic recovery, so it resists distortion when the registration is removed from the teeth and then later used to mount the models. This combination makes it the most reliable choice for precise bite registrations.

Alginate tends to undergo dimensional changes with water loss or uptake, leading to distortion. Wax readily distorts with temperature changes and handling. Zinc oxide–eugenol paste can creep and deform over time, reducing accuracy.