Cold Casting Mold With Venting Channels For Dental Parts

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Solution Overview

Problem

Current methods for producing dental parts using 3D printing are costly and inefficient, particularly for complex shapes and materials like ceramics and metals, due to high binder content requirements and the need for expensive 3D printers and isostatic presses, which limit the use of mixing masses with moisture content above 7%.

Innovation Solution

A cold cast shape with at least one second opening for gas and liquid exposure is created, allowing for even filling and ventilation, and made from organic materials with a melting point below 300°C, enabling cost-effective production of dental parts with varied materials and moisture contents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If conventional 3D printing methods are used to produce dental parts from ceramic or metal powders, then complex shapes can be achieved, but high binder content (approx. 30%) is required which increases production cost and limits material selection

Engineering Contradiction:
Improvecomplex shapeVSAvoidbinder content
Core Design Contradiction:
ShapeVSQuantity of substance

Solution Approach 1:

The patent extracts the binder from the mixing compound formulation, using only ceramic or metal powder without any binder additive. This eliminates the need for high binder content (approx. 30%) required by conventional 3D printing methods, thereby reducing production cost and allowing use of a broader range of materials including precious metals and technical ceramics.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the physical state parameter of the mixing compound from a slurry or paste (conventional methods requiring binder) to a dry powder state. This parameter change enables direct 3D printing without binder, solving the contradiction between achieving complex shapes and minimizing binder content.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If isostatic pressing is used to achieve sufficient dimensional stability of the mixing compound, then green body strength is improved, but the process complexity and equipment cost increase

Engineering Contradiction:
Improvedimensional stabilityVSAvoidprocess complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by optimizing the particle size distribution and moisture content of the ceramic or metal powder before 3D printing. This preliminary preparation ensures that the green body achieves sufficient dimensional stability directly after printing without requiring additional isostatic pressing equipment or complex post-processing steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses a disposable support structure made of water-soluble material that is removed after printing. This simple, low-cost approach provides temporary dimensional support during printing without requiring complex isostatic pressing equipment, thereby reducing device complexity while maintaining green body stability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Adaptability or versatility

If the mixing compound contains high moisture content (above 7%), then material versatility is improved, but drying efficiency decreases and production time increases

Engineering Contradiction:
Improvematerial versatilityVSAvoiddrying time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent incorporates a porous structure into the support framework of the printed part. This porous structure provides enhanced surface area for moisture evaporation during drying, significantly improving drying efficiency. The porous design allows high moisture content mixing compounds to be used with reduced drying time, resolving the contradiction between material versatility and production time.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent implements periodic heating cycles during the drying process, alternating between heating phases to evaporate moisture and cooling phases to prevent thermal stress. This periodic action accelerates moisture removal from high-moisture mixing compounds without compromising part integrity, thereby reducing total drying time while maintaining material versatility.

Inventive Principle:
Principle #19Periodic action

4Manufacturing precision

If expensive 3D printers and isostatic presses are used, then manufacturing precision is improved, but production cost increases

Engineering Contradiction:
Improvedimensional accuracyVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent replaces the mechanical isostatic pressing system with a chemical/biological approach using enzymatic treatment or controlled decomposition of the support structure. This substitution eliminates the need for expensive isostatic press equipment while maintaining sufficient green body strength and dimensional accuracy, thereby reducing production cost without sacrificing manufacturing precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses a digital twin or virtual simulation model to optimize the 3D printing parameters and support structure design before actual printing. This virtual copying and testing approach allows precise parameter optimization without requiring multiple expensive trial prints, thereby achieving high manufacturing precision while minimizing production cost.

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables the cost-effective production of dental parts with complex anatomical shapes and surface structures, expanding material use to ceramics, metals, and plastics, while reducing production costs and environmental humidity to enhance drying efficiency.

Implementation Method 1

wherein the cold casting mold is additively constructed from a starting material with a melting point below 300°C, in particular from an organic material, in particular a plastic or a polymer, so that the cold casting mold is plasticizable, in particular at a temperature in a temperature range from 35°C to 300°C, and/or is thermally and/or thermochemically decomposable

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

so that the cold casting mold is plasticizable, in particular at a temperature in a temperature range from 35°C to 300°C, and/or is thermally and/or thermochemically decomposable

Methodology Applied
Scientific EffectThermal decomposition: Pyrolysis

Data Source

PatentEP4048193B1Method for producing a cold-casting mould, and cold-casting mould for the production of moulded parts, in particular dentures
Publication Date: 2025.01.29 WDT WOLZ DENTAL TECH GMBH
  • EP4048193B1 patent drawingFigure 1~3
  • EP4048193B1 patent drawingFigure 4~6
  • EP4048193B1 patent drawingFigure 7~8

AI summary

The invention relates a method for producing a cold-casting mould (100) for the production of moulded dental parts (210) from a mixing compound (200), wherein the cold-casting mould (100), with a cavity (110) geometrically corresponding to the moulded dental part (210), is additively built up from a starting material (150) using a digital data record, on the basis of a spatial model of the oral cavity of a patient and of at least one first opening (111), which opens into the cavity (110) and is intended for being filled with the mixing compound (200), by means of an additive material building-up process, in particular a 3D printing process using a 3D printer (300). The invention also relates to the use or the production of such an additively built-up cold-casting mould (100) for a method for producing moulded dental parts (210) from a sinterable or light-curing mixing compound (200). The cold-casting mould (100) is additively built up with at least one second opening (112), which opens into the cavity (110) and/or leads out of the cavity (110) and is intended for discharging gases, in particular air inclusions (208), and or liquids, in particular diluents (207).