Ace the California RDA Written Exam 2026 – Drill, Fill, and Thrill Your Way to Success!

Light-cured acrylic resin provides the longest working time when constructing a custom impression tray. This is because it requires exposure to a light source for polymerization, which can be controlled by the dentist or dental assistant. In comparison, polyvinyl siloxane and alginates both have a relatively short working time as they begin to set immediately after mixing. Zinc oxide eugenol also has a fast setting time and is not suitable for constructing custom impression trays due to its rigidity and difficulty in removal from the mouth once set. Therefore, light-cured acrylic resin is the most suitable material for creating custom impression trays due to its extended working time and ease of manipulation.