The high-torque motor enables efficient and uniform mixing across a wide range of batch sizes. It delivers consistently homogeneous and reproducible results, even with high-viscosity or difficult materials. Mixing performance remains stable and accurate from 40 g to 1 kg.

The optimized paddle geometry ensures efficient and homogeneous mixing by leveraging centrifugal force to continuously move material into the ideal mixing zone.
Matching bowl sizes for different batch volumes ensure this effect is consistently applied, delivering uniform and reproducible results every time.

Twister offers a powerful motor pump or Venturi technology (Twister Venturi model) to maintain stable vacuum levels throughout every mix. This ensures controlled material behavior and prevents expansion issues caused by insufficient vacuum.
While many systems fall short of the required 90 mbar, Twister achieves approximately 60 mbar or better, delivering the vacuum performance needed for precise, repeatable results.

Step-by-Step Guide for Accurate, Bubble-Free Dental Models

Proper mixing of dental stone is essential for achieving accurate dental models and consistent results in digital and analog workflows. Incorrect mixing ratios or techniques can lead to porosity, internal stress, reduced strength, and inaccurate casts.

Follow these best practices to ensure optimal results:

1. Preparation

• Maintain a clean workspace: Dust, debris, or contaminants can negatively affect surface quality and model accuracy
• Use clean water at the correct temperature: Approximately 20–23 °C (68–73 °F) for consistent setting behavior
• Equalize material temperature: Ensure both powder and water are at similar temperatures to avoid delayed or inconsistent setting reactions

2. Follow the Correct Mixing Ratio

• Always follow the manufacturer’s specified water-to-powder ratio (e.g., 100 g powder to 30 ml water)
• Accurate measurement is critical and small deviations can significantly impact:
  • Flowability
  • Strength
  • Dimensional accuracy

3. Mixing Technique

• Add water first, then slowly incorporate the powder to minimize air entrapment
• Pre-mix manually for ~10 seconds to ensure full wetting and prevent clumping
• Mix mechanically—ideally under vacuum—to achieve a homogeneous, bubble-free consistency
• Typical mixing time: approximately 30–60 seconds (depending on material and device)

4. Processing & Pouring

• Work quickly: The setting reaction begins immediately after mixing
• Use gentle vibration during pouring to help release trapped air bubbles
• Avoid over-vibration, which can introduce defects
• Allow the model to set undisturbed and vibration-free for optimal surface quality and accuracy

5. Cleaning & Maintenance

• Clean bowls and tools immediately after use to prevent residue buildup
• Use appropriate cleaning solutions to maintain equipment performance
• Avoid aggressive chemicals that may damage surfaces or affect future mixes

Recommended Equipment for Best Results

For consistently homogeneous, dense, and low-porosity mixes, vacuum mixing is strongly recommended.

Renfert solutions:

• Twister Evolution – programmable vacuum mixing for precise, reproducible results
• Twister Venturi – compact, efficient vacuum mixing for smaller laboratories

These systems reduce air inclusion, improve material consistency, and significantly enhance model quality, especially in digital workflows requiring accurate scanning.