Interdental Brush Size Configuration Using PHD-Based Segmentation

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Solution Overview

Problem

Existing interdental brush sets lack systematic size selection criteria, leading to inconsistencies and potential tissue damage due to improper fit, especially in larger and irregularly shaped interdental spaces.

Innovation Solution

A set of interdental brushes is configured based on Passage Hole Diameter (PHD) measurements, using a cohort of professional raters to determine central tendency values, ensuring accurate sizing and moderate insertion forces through adjustments to wire diameter, brush diameter, and filament density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If interdental brush sizes are classified solely based on ISO PHD values, then standardization is achieved, but size distribution inconsistencies occur leading to gaps or excess similarities between available sizes

Engineering Contradiction:
Improvestandardization of brush sizingVSAvoidsize distribution consistency
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent changes the sizing parameter from ISO PHD classification alone to a multi-parameter system incorporating actual passage hole diameter measurements, brush diameter, and insertion force requirements. This allows precise control over size distribution while maintaining standardization, eliminating gaps and excess similarities between consecutive brush sizes in the set.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If a single PHD size is assigned to each brush, then classification simplicity is maintained, but accurate fit for varied interdental spaces cannot be ensured

Engineering Contradiction:
Improvebrush selection simplicityVSAvoidPHD size accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent segments the PHD measurement into multiple discrete size categories (e.g., PHD 0.6mm, 0.8mm, 1.0mm, etc.) rather than using a continuous scale. Each segment represents a specific brush size with defined characteristics, making selection straightforward while maintaining precise fit for different interdental space dimensions.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If brush sizes are reduced to fit smaller interdental spaces, then accessibility to tight spaces is improved, but cleaning effectiveness decreases due to insufficient brush contact area

Engineering Contradiction:
Improvefit for tight interdental spacesVSAvoidcleaning effectiveness
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies local quality by varying filament density and brush head geometry across different size categories. Smaller brushes (for tight spaces) maintain adequate cleaning effectiveness through increased filament density and optimized head shape, while larger brushes use appropriate filament spacing. Each brush in the set is locally optimized for its specific size category, ensuring both fit and cleaning reliability.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4663069A1An interdental brush set and method for determining the brush size configuration of said set
Publication Date: 2025.12.17 DENTAID
  • EP4663069A1 patent drawingFigure 1
  • EP4663069A1 patent drawingFigure 2
  • EP4663069A1 patent drawingFigure 3

AI summary

Set of interdental brushes comprising a plurality of interdental brushes (i1, i2, i3, i4, i5, i6, i7, i8, i9) distributed in size to increase within a range of values of Passage Hole Diameter (PHD), characterized in that the brush size of each of the interdental brushes (i1, i2, i3, i4, i5, i6, i7, i8, i9) of the set is configured to be assigned to a respective targeted value of Passage Hole Diameter (PHD) by performing a plurality of raters' measurements of Passage Hole Diameter (PHD) on an existing interdental brush, obtaining a statistical value of central tendency for said raters' measurements, and assigning the brush size configuration of the corresponding existing interdental brush to the respective targeted value when said statistical value of central tendency corresponds to the respective targeted value of Passage Hole Diameter (PHD).