Endodontic Instruments with Offset Center of Mass

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Traditional endodontic instruments with a coincident center of rotation and mass fail to effectively contact the entirety of the root canal walls, leading to incomplete preparation and increased risk of cyclic fatigue and breakage due to continuous contact and binding.

Innovation Solution

Designing endodontic instruments with a center of mass offset from the axis of rotation, creating a precessional cutting motion that generates a transverse mechanical wave, allowing for intermittent contact and reduced cyclic fatigue through a unique cross-sectional geometry and material properties like nickel-titanium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the center of mass is coincident with the axis of rotation, then the instrument structure is simple and stable, but the instrument fails to contact the entirety of the root canal walls and cannot effectively prepare difficult areas

Engineering Contradiction:

Improvecontact effectiveness with root canal wallsVSAvoidcenter of mass configuration

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by deliberately offsetting the center of mass from the axis of rotation. The working body is designed with an asymmetric cross-section where the center of mass lies at a distance from the rotational axis, creating an eccentric configuration. This asymmetric design enables the instrument to contact the root canal walls more effectively and access difficult areas while maintaining structural integrity.

Inventive Principle:

Principle #4Asymmetry

2Productivity

If the instrument continuously contacts the root canal walls, then cutting efficiency is improved, but cyclic fatigue and breakage risk increase

Engineering Contradiction:

Improvecutting efficiencyVSAvoidinstrument breakage resistance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements periodic action through the precessional motion generated by the offset center of mass. As the instrument rotates, the eccentric center of mass creates a periodic oscillation that causes intermittent contact with the root canal walls. This periodic contact pattern allows the instrument to maintain cutting efficiency while reducing continuous binding and cyclic fatigue accumulation, thereby lowering breakage risk.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The offset center of mass configuration generates mechanical vibration in the form of precessional motion. The vibrating working body creates dynamic contact with the root canal walls rather than static continuous contact. This vibration mechanism enables the instrument to cut effectively while distributing mechanical stress over time, reducing the risk of cyclic fatigue and instrument failure.

Inventive Principle:

Principle #18Mechanical vibration

3Adaptability or versatility

If the instrument diameter is increased to access difficult areas, then accessibility is improved, but the risk of cyclic fatigue and breakage increases

Engineering Contradiction:

Improveaccess to difficult areasVSAvoidcyclic fatigue resistance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies dynamics by creating a working body that can dynamically adjust its contact pattern with the root canal walls. The offset center of mass generates precessional motion that allows the instrument to adapt its engagement state between intermittent contact and cutting. This dynamic behavior enables the instrument to access difficult areas with larger effective diameter while maintaining lower cyclic fatigue through controlled intermittent engagement rather than continuous binding.

Inventive Principle:

Principle #15Dynamics

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 offset center of mass design enables more efficient and safer endodontic procedures by allowing for better access to difficult areas, reducing the risk of instrument breakage, and improving the thoroughness of root canal preparation while minimizing cyclic fatigue.

Implementation Method 1

Designing endodontic instruments with a center of mass offset from the axis of rotation, creating a precessional cutting motion that generates a transverse mechanical wave

Methodology Applied

Scientific EffectPrecession: Precession

Implementation Method 2

creating a precessional cutting motion that generates a transverse mechanical wave

Methodology Applied

Scientific EffectMechanical wave:

Implementation Method 3

material properties like nickel-titanium

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 4

reducing the risk of instrument breakage, and improving the thoroughness of root canal preparation while minimizing cyclic fatigue

Methodology Applied

Scientific EffectCyclic fatigue: Fatigue

Data Source

PatentUS11944513B2Endodontic instruments displaying compressibility

Publication Date: 2024.04.02 SCIANAMBLO MICHAEL J

AI summary

Endodontic instruments are used to clean and enlarge the endodontic cavity space (ECS), also known as the root canal system, of a human tooth. This document describes novel endodontic instruments that are radially compressible, and methods for their use. Some embodiments include a shank and a body with a working surface. At least a portion of the working surface may define a center of mass path that spirals. The center of mass of a transverse cross-section of the working surface at the shank end can be offset from the axis of rotation of the instrument.