Dental Aligner Thermoforming With Shape-Memory Repositioning

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Solution Overview

Problem

Existing methods for manufacturing dental aligners are not optimized, particularly in terms of efficiency and flexibility in producing aligners that can change shape to reposition teeth in a step-by-step manner.

Innovation Solution

A method involving two thermoforming steps with varying temperatures and pressures, using shape-memory materials, and unique identifiers for dental models and aligners to facilitate efficient production of aligners that store multiple shapes, allowing for random or batch-wise production without sequence constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional single-step thermoforming process is used to produce dental aligners, then the manufacturing process is simple, but multiple aligners are required for each treatment step, increasing production quantity and time

Engineering Contradiction:
Improveproduction efficiencyVSAvoidnumber of aligners needed
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The treatment plan is segmented into multiple treatment steps, with each aligner capable of performing multiple steps through sequential thermoforming. The aligner is divided into different shape states (first shape for intermediate position, second shape for target position), allowing one aligner to replace multiple traditional aligners.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the temperature parameter during sequential thermoforming processes. A first thermoforming is performed at a first temperature to create the intermediate shape, then a second thermoforming is performed at a second temperature to create the target shape. This parameter change enables the aligner to store multiple shapes and transition between them.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If multiple dental aligners are produced for each treatment step, then each aligner can be optimized for its specific step, but the manufacturing complexity and production time increase

Engineering Contradiction:
Improvetooth re-positioning precisionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The dental aligner is designed with multi-functionality to perform multiple treatment steps. Through sequential thermoforming processes, a single aligner can achieve both intermediate and target tooth positions, making it a universal tool that replaces multiple specialized aligners.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The aligner is pre-formed with the first shape representing the intermediate tooth position through initial thermoforming. This preliminary action prepares the aligner to guide tooth movement to the intermediate position before subsequent activation to the target position, enabling step-by-step treatment control.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If shape-memory materials are used to enable multi-shape aligners, then the number of aligners needed is reduced, but the material processing requirements and manufacturing difficulty increase

Engineering Contradiction:
Improvenumber of aligners neededVSAvoidmanufacturing ease
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent utilizes phase transitions of shape-memory materials through controlled temperature changes. The material transitions between different thermal states during sequential thermoforming, allowing it to be shaped into multiple configurations. This phase transition capability enables one aligner to store and deliver multiple treatment shapes.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The invention employs shape-memory materials that combine properties of traditional aligner materials with shape-memory capabilities. This composite material approach allows the aligner to be manufactured using modified conventional processes while gaining the ability to store and transition between multiple shapes.

Inventive Principle:
Principle #40Composite materials

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

Enables the production of dental aligners that efficiently reposition teeth through multiple shapes, reducing the number of aligners needed and simplifying the manufacturing process by using unique identifiers for model and aligner matching.

Implementation Method 1

carrying out a first thermoforming step of shaping an aligner material onto the second dental model to produce an aligner

Methodology Applied
Scientific EffectThermoforming: Heating

Implementation Method 2

The aligner material is preferably a shape-memory synthetic polymer (SMP) or metal material (shape memory alloy SMA)

Methodology Applied
Scientific EffectShape memory effect: Shape Memory Polymer

Implementation Method 3

carrying out a second thermoforming step of re-shaping the aligner onto the first dental model, wherein a second thermoforming temperature of the second thermoforming step is lower than a first thermoforming temperature of the first thermoforming step

Methodology Applied
Scientific EffectThermoforming: Heating

Implementation Method 4

From said second shape, the dental aligner will return into the previous, first shape once a stimulus, e.g. temperature or humidity, are applied thereto

Methodology Applied
Scientific EffectShape recovery: Shape Memory Polymer

Data Source

PatentEP4509091B1Method of producing a dental aligner and production line thereto
Publication Date: 2026.05.06 K LINE EURO GMBH
  • EP4509091B1 patent drawingFigure 1
  • EP4509091B1 patent drawingFigure 2

AI summary

The invention refers to a method of producing a dental aligner for a treatment plan with at least an actual position and a target position of a tooth to be re-positioned and to a production line to produce such a dental aligner. To propose an improvement of the manufacturing method and equipment for a dental aligner or sets of dental aligners it is provided that the method comprises the steps of - producing a set of dental models comprising at least - a first dental model based on the actual position and - a second dental model based on the target position; - carrying out a first thermoforming step of shaping an aligner material onto the second dental model to produce an aligner; - removing the aligner from the second dental model; - placing the aligner on the first dental model; - carrying out a second thermoforming step of re-shaping the aligner onto the first dental model, - wherein a second thermoforming temperature of the second thermoforming step is lower than a first thermoforming temperature of the first thermoforming step.