What are the best acrylic resins to make dentures or stay plates?

No best : Resins used to make dentures are very generic as to materials very little in composition. It is sad that dentists try to use the material in the denture base to differentiate a cheap versus a deluxe denture. The expense to the dentist from the lab for a customize base resin is small and can lead to deception in its cost. Yet, adding blanching, pigment and fiber can improve cosmetics. Be aware.

Depends on time: If the prosthesis is to last a long time then heat cured acrylic resins with multibranced polymerization are very durable and cosmetic and relatively small processing errors. For short term prosthesis i prefur triad light cured materials over cold cure acrylics. More accurate, less mess, no volatile liquids to spill or inhale.

Ask your dentist: There a different materials but for acrylic i like lucitone 199.