Dental Shade Key Alignment via Asymmetrical Marking and Virtual Templates

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The accurate determination of tooth color for prosthetic teeth is challenging due to factors like translucency, brightness, and metamerism, which are influenced by lighting and viewing angles, making it difficult to achieve a natural appearance that matches adjacent natural teeth.

Innovation Solution

A method is developed to align a camera or scanning device with a dental auxiliary element, such as a mini shade key, using intelligent software and image processing to maintain constant distance, alignment, and viewing angle, employing asymmetrical markings and templates for precise color determination, and utilizing virtual templates to simplify storage and alignment processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If photographs are taken to determine tooth color, then color determination is possible, but accuracy is reduced due to varying lighting conditions and viewing angles

Engineering Contradiction:
Improvetooth color determination accuracyVSAvoidlighting conditions and viewing angle variations
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by pre-defining the correct camera position and orientation relative to the shade guide using asymmetrical markings and templates. The system prepares alignment guides and virtual templates in advance, allowing the operator to position the camera correctly before capturing the tooth color image. This ensures that lighting conditions and viewing angles are optimized prior to measurement, thereby improving color determination accuracy while minimizing the harmful effects of variable lighting and angles.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If manual alignment methods are used, then operation is simple, but measurement precision and alignment consistency are reduced

Engineering Contradiction:
Improvealignment precisionVSAvoidalignment system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs copying by creating a virtual template that replicates the asymmetrical marking pattern on the shade guide. Instead of requiring complex physical alignment tools, the system captures an image of the shade guide with its asymmetrical marking, processes it to create a virtual template, and uses this digital copy for automated alignment verification. This approach achieves high measurement precision through image processing and pattern recognition while keeping the physical device relatively simple.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces manual mechanical alignment procedures with an automated image processing system. The asymmetrical markings and virtual templates enable the camera to automatically determine its position and orientation relative to the shade guide through software-based pattern recognition rather than requiring manual adjustment of mechanical components. This substitution of mechanical alignment with computational methods improves both precision and consistency.

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

3Measurement precision

If physical templates are used for alignment, then alignment accuracy is improved, but device complexity and storage requirements increase

Engineering Contradiction:
Improvealignment accuracyVSAvoidtemplate management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces physical templates with virtual templates stored in computer memory. The asymmetrical marking pattern from the shade guide is captured as an image and processed to create a digital template that can be stored, reproduced, and manipulated software-based. This eliminates the need for multiple physical template sets and their associated storage and management complexity while maintaining alignment accuracy through precise digital image processing and pattern matching.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP3558160B1Camera alignment or scanning apparatus method with a dental reference element
Publication Date: 2021.03.31 IVOCLAR VIVADENT AG
  • EP3558160B1 patent drawingFigure 1~2
  • EP3558160B1 patent drawingFigure 3a~4c
  • EP3558160B1 patent drawingFigure 5

AI summary

The invention relates to a method for approaching an aligned relative position between a camera or scanning device and a dental ancillary element (10), in particular via an App on a Smart phone, for the recording of the dental ancillary element (10), such as a mini colored key (10). A marking (4) is applied to the dental ancillary element (10), and/or at least one part of the dental ancillary element (10) is used as a marking (4). A template (6) that is congruent with the marking (4) or mathematically similar is blended in on a display device of the camera or scanning device. For the approach to the aligned relative position between the camera or scanning device and the dental ancillary element, a change in the level of coverage of the template (6) with the marking (4) or the one part of the dental ancillary element (10) is detected.