Dual-Wavelength Dental Curing Light for Low-Heat Polymer Hardening

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Solution Overview

Problem

Existing dental devices for hardening polymers are inefficient and energy-intensive, lacking in surface finish quality and material compatibility, and struggle with effective curing at varying distances.

Innovation Solution

A dental handheld device utilizing a combination of a laser diode emitting light in a first wavelength range (440-460 nm) and a light-emitting diode emitting light in a second wavelength range (400-420 nm), with the laser diode having a higher radiant power, to achieve efficient and energy-saving polymer hardening with improved surface finish and penetration depth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a conventional light source is used for curing polymers, then the device can harden the polymer, but heat generation is high and energy consumption is high

Engineering Contradiction:
Improveheat generationVSAvoidcuring efficiency
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The patent applies parameter changes by selecting specific wavelength ranges (400-420 nm and 440-460 nm) for the light sources that match the absorption characteristics of polymer initiators. This wavelength optimization enables efficient curing while minimizing heat generation, as the energy is absorbed more effectively by the chemical bonds rather than converting to thermal energy.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite light source system combining two different light sources (LED or laser diode) with complementary wavelength ranges. This composite approach creates a broader spectrum output that efficiently cures various polymer materials while reducing overall heat generation compared to single high-power sources.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If a single light source is used, then the device structure is simple, but the curing spectrum is limited and surface quality is reduced

Engineering Contradiction:
Improvecuring spectrumVSAvoiddevice structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges two light sources with different wavelength ranges into a single handheld device. The first light source (400-420 nm) and second light source (440-460 nm) are combined in close proximity, allowing simultaneous or sequential operation to cure polymers with a broader spectrum, thereby improving surface quality and adaptability to different materials.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The dual-light-source design provides multi-functionality by enabling the device to effectively cure various polymer materials with different initiator systems. The broader spectral output accommodates different photoinitators, making the device universally applicable to diverse dental materials while maintaining a compact structure.

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

3Length of moving object

If light diverges significantly, then the device can illuminate a larger area, but the curing effectiveness at distance is reduced

Engineering Contradiction:
Improvecuring distanceVSAvoidlight divergence
Core Design Contradiction:
Length of moving objectVSIllumination intensity

Solution Approach 1:

The patent employs laser diodes which inherently produce highly directional, low-divergence light beams. This dynamic optical property allows the light to maintain high intensity over extended distances, enabling effective curing of polymers at greater depths and distances without significant loss of illumination intensity.

Inventive Principle:
Principle #15Dynamics

4Productivity

If high power light source is used, then the curing speed is fast, but energy consumption increases and battery size increases

Engineering Contradiction:
Improvecuring speedVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent optimizes the operating parameters of LED or laser diode light sources by selecting specific wavelength ranges (400-420 nm and 440-460 nm) that align with polymer initiator absorption peaks. This parameter optimization achieves high curing efficiency and fast curing speeds while consuming less energy, as the light energy is more effectively converted into chemical bonding rather than wasted as heat or other losses.

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

The device provides efficient curing with reduced heat generation, increased surface finish quality, and compatibility with various materials, enabling effective hardening at greater distances and reduced energy consumption.

Implementation Method 1

a first light source (101-1), which includes a laser diode for emitting light in a first wavelength range (103-1)

Methodology Applied
Scientific EffectLight emission from laser diode: Laser

Implementation Method 2

dental handheld device for curing a polymer using light

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 3

a second light source (101-2) for emitting light in a second wavelength range (103-2)

Methodology Applied
Scientific EffectLight emission from LED or laser diode: Light Emitting Diode

Implementation Method 4

the dental handpiece comprises a bundle of light-conducting fibers (121)

Methodology Applied
Scientific EffectLight conduction through optical fibers: Optical Fibre

Implementation Method 5

the dental handpiece includes a beam coupler for superimposing the light beams of the two light sources

Methodology Applied
Scientific EffectLight beam superposition: Interference

Data Source

PatentEP4275650B1Dental hand tool for curing a polymer
Publication Date: 2026.04.29 IVOCLAR VIVADENT AG
  • EP4275650B1 patent drawingFigure 1
  • EP4275650B1 patent drawingFigure 2
  • EP4275650B1 patent drawingFigure 3

AI summary

The present invention relates to a dental hand device (100) for hardening a polymer by means of light, comprising a first light source (101-1) comprising a laser diode for emitting light in a first wavelength range; and a second light source (101-2) for emitting light in a second wavelength range.