The analog fabrication of a dental model involves several structured steps that are coordinated to ensure high precision:

1. Mixing the dental stone
   The model stone is mixed under vacuum to achieve a homogeneous, bubble-free consistency. This forms the foundation for a stable and highly detailed model.
2. Pouring and compacting
   The stone is poured into the prepared mold and compacted using vibration to eliminate air bubbles and ensure a uniform structure.
3. Trimming the model contours
   Once set, the model base is trimmed to create clean contours and an accurate fit. A dental arch trimmer is used to reduce the model to the dental arch before mounting it on a model base.
4. Pin drilling and base mounting
   Precise holes are drilled into the model base to allow for later segmentation of the model. The model base provides a stable foundation for further processing.
5. Saw-cutting and die preparation
   The model is sectioned into individual segments. The dies are then prepared to ensure an accurate fit for the final restoration.
6. Dust extraction
   Fine stone dust is generated during processing which must be collected using appropriate extraction systems to maintain a clean and healthy working environment.

Renfert offers specialized equipment to support each step of this workflow.

• Twister: Vacuum mixer for stone preparation
• Vibrax: Vibrator for compacting
• Millo – Dental arch trimmer for trimming the outer contours of sectioned models
• AUTO spin:  Pin drilling system for model base mounting
• Plastercut: Diamond cutting discs for die separation
• die:master: Components for die preparation
• SILENT compact and Vortex compact 3L: extraction units for dry and wet applications

Step-by-step guide to mixing dental stone correctly

Proper mixing of dental stone is crucial for the quality of dental models.  Errors in the mixing ratio or technique can lead to porosities, internal stress, or inaccurate casts. Follow these key steps for optimal results:

1. Preparation

• Clean workspace: Dust and contaminants can compromise the quality of the stone.
• Water quality and temperature: Use clean tap water at approximately 20–23 °C (68–73 °F).
• Equalize material temperature: Stone and water should be at similar temperatures to avoid delayed setting reactions.

2. Observe the mixing ratio

• The mixing ratio depends on the product and is usually given as a water-to-powder ratio, e.g.,  100 g of stone to 30 ml of water.
• Accurate weighing is essential – even small deviations can significantly affect flowability and strength.

3. Mixing

• Add water to the mixing bowl first, then slowly sprinkle in the stone.
• Pre-mix manually with a spatula for about 10 seconds to prevent clumping.
• Then mix mechanically, ideally under vacuum, to eliminate air bubbles. Mixing time varies by device and material, typically 30–60 seconds.

4. Processing

• Use the stone immediately after mixing, as the setting process begins quickly.
• Vibration helps remove air bubbles during pouring.
• After pouring, allow the model to set undisturbed and vibration-free.

5. Cleaning

• Clean the mixing bowl and tools immediately after use to prevent material buildup.
• For particularly fast and thorough cleaning, use the GO 2011 speed cleaning agent. It effectively dissolves stone residues while protecting tool surfaces at the same time.
• Avoid aggressive cleaners, as they may damage surfaces.

Recommended equipment for optimal results

For a homogeneous, bubble-free mix, Renfert recommends using vacuum mixing devices such as:

• Twister evolution – For precise and reproducible mixing using a vacuum pump
• Twister venturi – Compact and efficient for smaller labs

These devices ensure consistent texture and minimize air entrapment, significantly improving model quality.