Dental Plaque and Calculus Detection Using Blue-Light Autofluorescence

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Dental plaque and calculus are difficult to identify visually, necessitating a method and device to distinguish them effectively.

Innovation Solution

A method and device utilizing a light-emitting diode to emit light within specific wavelength bands, generating autofluorescence in plaque and calculus, which is sensed by an image sensor and processed to differentiate plaque and calculus areas based on distinct autofluorescence cycles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If visual inspection is used to identify dental plaque and calculus, then the method is simple and quick, but the identification accuracy is poor because plaque and calculus are not easy to identify with the naked eye

Engineering Contradiction:
Improvesimplicity of identification methodVSAvoididentification accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent utilizes autofluorescence color changes to distinguish plaque and calculus. When excited by blue light (380-480nm), plaque and calculus emit yellow-green fluorescence (500-560nm), which is easily distinguishable from normal tooth structure. This optical color change enables accurate visual identification without complex procedures.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent introduces an optical intermediary system consisting of a blue light source and a camera sensor to mediate the detection process. The light source excites the autofluorescence of plaque and calculus, while the camera captures the emitted fluorescence, serving as an intermediary between the target object and human observation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If advanced optical detection methods are used to improve identification accuracy, then the detection precision improves, but the device complexity increases

Engineering Contradiction:
Improvedetection accuracyVSAvoiddevice structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs a camera module that can capture both regular visible light images and autofluorescence images. This multi-functional device allows switching between normal visual inspection and fluorescence-based detection, eliminating the need for separate specialized equipment and reducing overall system complexity.

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

Solution Approach 2:

The patent utilizes the inherent autofluorescence property of plaque and calculus as a self-service detection mechanism. The tissue itself provides the fluorescent signal when excited by appropriate wavelength light, eliminating the need for external contrast agents, dyes, or complex staining procedures that would increase device and procedural complexity.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If multiple wavelength light sources are used to enhance detection capability, then the detection versatility improves, but the energy consumption and device complexity increase

Engineering Contradiction:
Improvedetection capabilityVSAvoidlight source energy consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by using a specific wavelength range (380-480nm blue light) that is optimally suited for exciting the autofluorescence of dental plaque and calculus. Rather than using broad-spectrum or multiple wavelength sources, the system focuses energy on the most effective wavelength range, reducing overall energy consumption while maintaining high detection capability.

Inventive Principle:
Principle #3Local quality

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 accurate identification and differentiation of plaque and calculus areas on teeth, facilitating effective oral care.

Implementation Method 1

emitting, by a light-emitting diode, light to illuminate teeth in an oral cavity

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Implementation Method 2

the light is used to generate autofluorescence of plaque and calculus on the teeth

Methodology Applied
Scientific EffectAutofluorescence: Fluorescence

Implementation Method 3

sensing, by an image sensor, the autofluorescence of plaque and calculus

Methodology Applied
Scientific EffectFluorescence detection: Fluorescence

Data Source

PatentEP3785607B1Method and device for distinguishing plaque and calculus
Publication Date: 2025.11.12 QUANTA COMPUTER INC
  • EP3785607B1 patent drawingFigure 1
  • EP3785607B1 patent drawingFigure 2
  • EP3785607B1 patent drawingFigure 3

AI summary

A method for distinguishing plaque and calculus is provided. The method is used in a device and includes the following steps: emitting, by a blue light-emitting diode, blue light to illuminate teeth in an oral cavity, wherein the blue light is used to generate autofluorescence of plaque and calculus on the teeth; sensing, by an image sensor, the autofluorescence of plaque and calculus; and distinguishing, by a processor, a plaque area and a calculus area on the teeth based on the autofluorescence.