Handheld Light-Curing Device with Reflected Signal Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current light curing devices for dental materials, especially handheld units, face challenges in ensuring reliable polymerization due to user handling errors, leading to incomplete curing and material shrinkage, which can result in edge gaps and potential health risks from free radicals.

Innovation Solution

The device automatically detects changes in reflected light signals to correct for misalignment and adjust light output or polymerization time, ensuring consistent curing by monitoring the light dose received by the dental restoration and sending location correction signals to the practitioner.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the polymerization time is extended to ensure complete curing, then the reliability of polymerization is improved, but the material shrinkage increases leading to marginal gaps

Engineering Contradiction:
Improvepolymerization completenessVSAvoidmarginal gaps
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The device uses sensors to detect the reflected radiation from the dental restoration during polymerization. The control device continuously monitors this feedback signal and adjusts the light emission in real-time to achieve complete curing while minimizing over-polymerization and associated shrinkage.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the light emission parameters (intensity, duration) based on the detected polymerization progress. By monitoring the reflected radiation profile and identifying when polymerization is complete, the system avoids excessive curing time that would cause additional shrinkage and marginal gaps.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the light output is increased to speed up polymerization, then the productivity is improved, but the uniformity of curing decreases

Engineering Contradiction:
Improvepolymerization speedVSAvoidcuring uniformity
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The light emission is made dynamic rather than static. The control device adjusts the light output in real-time based on feedback from sensors monitoring the polymerization progress, allowing the system to adapt to varying material properties and restoration geometries throughout the curing process.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Sensors detect the reflected radiation to monitor polymerization progress. This feedback enables the control device to maintain optimal light output levels that ensure uniform curing while completing the process efficiently.

Inventive Principle:
Principle #23Feedback

3Area of stationary object

If the light-curing device is moved during polymerization to cover the entire restoration, then the area coverage is improved, but the measurement precision of polymerization progress decreases

Engineering Contradiction:
Improverestoration coverageVSAvoidpolymerization detection accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The sensor system is designed to detect reflected radiation from multiple positions and angles. This multi-functional detection capability allows accurate monitoring of polymerization progress even when the light-curing device is moved to cover different areas of the restoration.

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

Solution Approach 2:

The continuous feedback from sensors monitoring reflected radiation enables the system to track polymerization progress accurately regardless of device position. The control device uses this feedback to determine when complete curing has been achieved across the entire restoration surface.

Inventive Principle:
Principle #23Feedback

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 allows for reliable and uniform polymerization, reducing the risk of incomplete curing and material shrinkage, while informing practitioners of potential areas needing post-curing, thus improving restoration quality without complex test series.

Implementation Method 1

Polymerization occurs when a photoinitiator matching the emission maximum – for example, camphorquinone – triggers the polymerization reactions

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

devices that detect the reflection of light from objects exposed to the light-curing device

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3357452B1Light hardening device
Publication Date: 2021.05.19 IVOCLAR VIVADENT AG
  • EP3357452B1 patent drawingFigure 1~3
  • EP3357452B1 patent drawingFigure 4~6

AI summary

The invention relates to a light-curing device with a light source arranged in the handheld light-curing device, and in particular comprising a plurality of adjacent and adjoining chips forming a light source, in front of which a light guide extends, with at least one sensor sensitive to light in the emission wavelength range of the light source, and with a control device for controlling the light source during polymerization, to which the sensor is connected, wherein the control device continuously or at least periodically monitors the output signal of the sensor during polymerization and adjusts the light power and/or the polymerization time when the output signal is reduced, and wherein the control device sums the reflected radiation detected via the light emission surface 10 to calculate any positional deviation.and that the light emission area 10 of the light guide is larger than or equal to the largest dental restoration 12 to be cured, in particular having a cross-sectional area of ​​more than 1 cm2.