Glass-Ceramic Dental Restorations With Tunable Translucency

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Solution Overview

Problem

Existing dental materials struggle to achieve optical properties that closely match natural teeth and maintain mechanical strength and chemical resistance, especially when applied to discolored tooth stumps, and existing processes do not allow for individual adaptation in a dentist's practice.

Innovation Solution

A multi-step thermal treatment process for glass ceramics, including specific temperature and duration controls, allows for the production of dental restorations with adjustable optical and mechanical properties, enabling precise matching to individual patient needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If glass infiltration ceramics or opaque variants are used to achieve higher opacity, then light transmittance is reduced, but mechanical properties deteriorate due to separate phase formation

Engineering Contradiction:
Improvelight transmittanceVSAvoidmechanical properties
Core Design Contradiction:
Illumination intensityVSStrength

Solution Approach 1:

The patent applies parameter changes by precisely controlling thermal treatment parameters (temperature, time, atmosphere) to achieve the desired opacity without forming separate phases. The multi-step thermal treatment process modifies the glass ceramic structure to obtain the right balance between light transmittance and mechanical strength.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by creating specific microstructural zones within the glass ceramic material. Through controlled crystallization and phase separation, different regions with distinct optical properties are formed while maintaining overall structural integrity and mechanical strength.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If masking fixing materials are used to conceal dark stumps, then opacity is increased, but optical properties of the natural stump are blocked

Engineering Contradiction:
ImproveopacityVSAvoidoptical properties matching
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the optical properties of the glass ceramic adjustable and adaptable. The multi-step thermal treatment process allows for fine-tuning of translucency and color to match the patient's natural teeth, providing a dynamic solution rather than a fixed opaque material.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses parameter changes in the thermal treatment process to achieve the desired optical properties. By adjusting temperature, time, and atmospheric parameters, the material's translucency and color can be precisely controlled to match natural teeth while maintaining adequate opacity for discolored stumps.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If additives are used to adjust opacity, then light transmittance is reduced, but the additives form separate phases that deteriorate mechanical properties

Engineering Contradiction:
ImproveopacityVSAvoidphase homogeneity
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by optimizing the composition and thermal treatment parameters to achieve opacity without separate phase formation. The controlled thermal process transforms the material structure to obtain the desired optical properties while maintaining compositional homogeneity and mechanical integrity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies the extraction principle by removing harmful separate phases through controlled thermal treatment. The process extracts or eliminates unwanted phase separations that would otherwise deteriorate mechanical properties, while retaining the beneficial opacity-enhancing characteristics.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The process enhances mechanical properties like biaxial strength and allows for controlled translucency adjustment, resulting in dental restorations that closely resemble natural teeth and withstand oral conditions.

Implementation Method 1

The workpiece is subjected to a thermal treatment in a first thermal treatment step at a temperature T1 for a duration t1, followed by a second thermal treatment step at a temperature T2 for a duration t2

Methodology Applied
Scientific EffectThermal treatment: Heat Treatment

Implementation Method 2

The thermal treatment includes a nucleation step at a temperature Tn and a duration tn

Methodology Applied
Scientific EffectNucleation: Nucleation

Implementation Method 3

The thermal treatment includes a crystallization step at a temperature Tc and a duration tc

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Data Source

PatentEP3365292B1Process for producing a workpiece with low translucency
Publication Date: 2025.10.15 VITA ZAHNFABRIK H RAUTER GMBH & CO KG
  • EP3365292B1 patent drawingFigure 1

AI summary

The present invention relates to a process for producing a workpiece made of glass ceramics, and to the workpiece obtainable by the process according to the invention. Further, the invention relates to the use of the workpiece obtained as a dental restoration, and to a process allowing the translucency of a workpiece to be controlled.