Endodontic Handpiece Sinusoidal Acceleration Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current endodontic handpieces experience mechanical jerks and vibrations during rapid direction changes, leading to musculoskeletal strain for dentists, potential file breakage, and incomplete debris removal due to abrupt rotation reversals, which can result in tooth loss and abscesses.

Innovation Solution

The apparatus controls the oscillatory movement of the endodontic file with sinusoidal acceleration at direction changes and employs adaptive control to reduce working angles when high torque is engaged, using a contra angle with a low reduction ratio and integrating a detection system for the root apex to prevent breach.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the endodontic file is rotated rapidly in opposite directions to remove organic debris, then the debris removal efficiency is improved, but mechanical jerks and vibrations occur causing musculoskeletal strain and potential file breakage

Engineering Contradiction:
Improvedebris removal efficiencyVSAvoidfile breakage risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts the rotation parameters including speed, acceleration, and arc length of rotation based on real-time torque feedback. When high torque is detected indicating file engagement with canal walls, the system automatically reduces working angles and adjusts rotation characteristics to prevent file breakage while maintaining debris removal effectiveness

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates torque sensing that provides continuous feedback on file engagement with the root canal. This feedback loop allows the control system to monitor loading conditions and automatically adjust rotation parameters, preventing excessive forces that could cause file breakage while maintaining effective debris removal

Inventive Principle:
Principle #23Feedback

2Productivity

If the file is rotated in opposite directions with different arc lengths to facilitate debris extraction, then the debris removal is improved, but mechanical stress and vibrations increase causing operator strain

Engineering Contradiction:
Improvedebris extraction efficiencyVSAvoidoperator musculoskeletal strain
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The system dynamically controls the rotation parameters including varying the arc length in different directions and adjusting rotation speed throughout the cycle. This dynamic control smooths out mechanical jerks and vibrations while maintaining the asymmetric arc lengths needed for effective debris extraction, reducing operator strain

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes multiple parameters simultaneously including rotation speed, acceleration profiles, and arc lengths during the oscillatory cycle. By optimizing these parameters dynamically, the system achieves effective debris removal with reduced mechanical stress and vibrations transmitted to the operator

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the rotation speed is increased to improve debris removal, then the productivity increases, but the risk of pushing the file beyond root apex and breaching the proximal root portion increases

Engineering Contradiction:
Improvedebris removal speedVSAvoidapex breach risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The torque sensing system provides real-time feedback on file engagement and resistance. When the file approaches the root apex, the increased resistance is detected as torque change, triggering automatic adjustment of rotation parameters or cessation of rotation to prevent apex breach while maintaining effective debris removal at safer speeds

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3338727B1Endodontic handpiece
Publication Date: 2024.01.31 CEFLA SOC COOP
  • EP3338727B1 patent drawingFigure 1~2
  • EP3338727B1 patent drawingFigure 3~4
  • EP3338727B1 patent drawingFigure 5~6

AI summary

A method for controlling an endodontic instrument, wherein an endodontic file (11) mounted on an assembly micromotor (8)-contra angle (9) is rotated in a first direction (working angle, δ) and successively in the opposed direction (unloading angle, η) with an alternated movement. According to the invention, the inversion of the direction of rotation occurs with sinusoidal acceleration of the speed of rotation, from zero to the working value. System comprising a micromotor (8) and a contra angle (9) with alternated movement of an endodontic file (11) in a first direction (working angle, δ) and successively in the opposed direction (unloading angle, η) within an alternated movement, characterized in that it, comprises a control unit (60) of said micromotor rotation, generating a control signal of the acceleration of said micromotor with the shape of a sinusoid wave causing the inversion of the direction of rotation occurs with sinusoidal acceleration of the speed of rotation, from zero to the working value.