Force-Responsive Microcapsules for Aligner Change Timing

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Solution Overview

Problem

Existing aligner therapy for misaligned teeth lacks a reliable method to determine treatment effectiveness, monitor progress, and adjust aligner changes, as the force applied by plastic aligners diminishes over time, affecting treatment consistency.

Innovation Solution

Microcapsules with biocompatible shells filled with a detectable liquid that rupture at defined forces, allowing optical detection of force application, enabling effective treatment monitoring and aligner change timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If plastic aligners are used to treat tooth misalignment, then the treatment is largely invisible and aesthetically pleasing, but the force applied by the aligners diminishes over time, reducing treatment effectiveness

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidforce consistency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent incorporates microcapsules that rupture in response to force application, providing visual feedback to both clinicians and patients about the current force level. This feedback mechanism allows real-time monitoring of aligner effectiveness and triggers timely interventions when force diminishes, resolving the contradiction between aesthetic appearance and force consistency.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The microcapsules contain dyes that change color or become visible when ruptured due to force application. This color change provides a clear visual indicator of force levels, enabling patients and doctors to monitor treatment progress and adjust aligner usage accordingly, maintaining reliable force application while preserving the aesthetic design of the aligners.

Inventive Principle:
Principle #32Color changes

2Reliability

If new aligners are used at regular intervals to maintain treatment effectiveness, then consistent treatment can be ensured, but the complexity of tracking treatment progress and determining optimal change timing increases

Engineering Contradiction:
Improvetreatment consistencyVSAvoidmonitoring complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The microcapsules provide self-monitoring functionality, automatically indicating when force application has diminished without requiring external monitoring systems. The visual feedback is directly provided by the aligner itself through capsule rupture, eliminating the need for complex electronic sensors, apps, or frequent clinical visits to assess treatment progress.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The visual color change or appearance of microcapsule contents provides an immediate, intuitive indicator of treatment status. This simple visual signal replaces complex digital monitoring systems, allowing patients to independently track treatment progress and determine when aligner changes are needed, reducing monitoring complexity while maintaining treatment consistency.

Inventive Principle:
Principle #32Color changes

3Reliability

If the force applied by aligners is increased to compensate for material deformation, then treatment effectiveness is maintained, but the risk of exceeding maximum force limits and causing tooth damage increases

Engineering Contradiction:
Improvetreatment effectivenessVSAvoidtooth damage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The microcapsules provide real-time feedback on force application levels, allowing patients and clinicians to monitor whether forces are within safe limits. When capsules rupture, it indicates that force thresholds have been exceeded, triggering immediate action to reduce force application and prevent tooth damage, thus balancing treatment effectiveness with safety.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The microcapsules are designed with specific rupture force parameters that correspond to safe treatment limits. By changing the physical state of the capsule (from intact to ruptured) at specific force thresholds, the system provides automated warnings when approaching harmful force levels, enabling dynamic adjustment of force application to stay within safe parameters while maintaining treatment effectiveness.

Inventive Principle:
Principle #35Parameter changes

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 real-time monitoring of force application on teeth, ensuring consistent treatment efficacy by visually indicating when to change aligners, allowing both doctors and patients to make informed decisions.

Implementation Method 1

The shell ruptures when subjected to a defined force, releasing the liquid, which can be detected optically

Methodology Applied
Scientific EffectForce-induced rupture: Fracture Mechanics

Implementation Method 2

A color change can occur due to a change in pH or oxidation of the dye.

Methodology Applied
Scientific EffectpH change:

Implementation Method 3

A color change can occur due to a change in pH or oxidation of the dye.

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP4140441B1Microcapsule for use in the treatment of tooth misalignment by means of plastic splints or aligners
Publication Date: 2026.03.04 DENTSPLY SIRONA INC
  • EP4140441B1 patent drawingFigure 1
  • EP4140441B1 patent drawingFigure 2~3

AI summary

The present invention relates to a microcapsule (1) for use in the treatment of dental misalignments by means of plastic splints (5) or aligners (5), characterized in that the microcapsule (1) is a few µm in size, preferably 0.5µm to 200µm, and has a shell (2) made of plastic or glass or ceramic, the shell (2) being filled inside with a liquid (3), and the shell (2) breaking open when it is subjected to a defined force and releasing the liquid (3), which can be optically detected, preferably by a color change or illumination with UV light.