Root Canal File with Semi-Guiding Tip and Variable Taper
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Solution Overview
Problem
Ordinary single-taper root canal files face issues such as blockage due to dentin debris, complications like step, deviation, and perforation during root canal preparation, primarily due to poor guiding at the root tip and increased resistance.
Innovation Solution
A root canal file with a round blunt semi-guiding tip, variable taper, and a combination of uncut and cut sections with blade-shaped cross-sections, featuring reverse threads for reciprocating motion, enhances cutting efficiency and debris removal while minimizing blockage and instrument breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ordinary single-taper root canal files are used, then the instrument can penetrate into the root canal, but the resistance to dentin removal increases near the root tip causing blockage
Solution Approach 1:
The root canal file is divided into multiple sections with different thread pitches and depths. The apical third has finer threads for gentle engagement, while the coronal thirds have progressively coarser threads for more aggressive cutting. This segmentation allows the file to remove dentin efficiently while progressively engaging the canal walls, preventing debris push-back and blockage.
Solution Approach 2:
Different sections of the root canal file have locally optimized properties: the tip portion has a smaller diameter and finer threads for navigation and initial engagement, while successive sections have increasing diameters and coarser threads for progressive cutting. This local quality variation allows each section to perform its specific function optimally without causing blockage.
2Productivity
If ordinary root canal files with sharp tips are used, then cutting efficiency is improved, but complications such as step, deviation, and perforation occur due to poor guiding
Solution Approach 1:
The file design includes a transitional zone between the tip and the threaded portion, and the threads progressively engage the canal walls from the apex upward. This preliminary engagement action guides the file along the natural canal path before aggressive cutting begins, preventing deviation and perforation while maintaining cutting efficiency.
Solution Approach 2:
The thread parameters (pitch, depth, angle) are progressively changed from the apical to coronal sections. The finer threads at the apex provide better guidance and control, while the coarser threads in the coronal sections provide more aggressive cutting. This parameter progression maintains reliability while improving cutting efficiency.
3Ease of manufacture
If root canal files with uniform taper are used, then manufacturing is simplified, but cutting performance and adaptability to different canal shapes are reduced
Solution Approach 1:
The file is segmented into multiple cylindrical sections, each with uniform thread parameters, making each section manufacturable with standard processes. The segmentation into distinct functional zones (tip, transitional zone, threaded portions with different pitches) balances manufacturing simplicity with adaptability to various canal geometries.
4Device complexity
If root canal files push dentin debris to the root tip are used, then debris removal seems simplified, but blockage occurs and instrument breakage risk increases
Solution Approach 1:
Instead of pushing debris apically toward the root tip, the progressive thread design allows debris to be cut and retained in the coronal portions of the file during withdrawal. The file effectively pulls debris out of the canal rather than pushing it in, inverting the traditional debris management approach and eliminating blockage and breakage risks.
Data Source
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AI summary
The present invention provides a root canal file, which includes a working part and a handle. The working part includes a tip portion, a threaded portion and a non-threaded portion. The tip portion is a round blunt semi-guiding tip, the threaded portion includes an uncut section and a cut section, the tip portion, the uncut section, the cut section and the non-threaded portion are connected in sequence, and the non-threaded portion is connected to the handle. The tip portion is the round blunt semi-guiding tip, which makes the root canal file have a certain cutting ability during use, while ensuring the original form of a root canal, thus avoiding the complications such as step, deviation, and perforation during root canal preparation. The working part further includes the threaded portion, and the threaded portion includes the uncut section and the cut section; due to the cut face design, a debris space of the root canal file is enlarged, and the problem of blockage caused by pushing dentin debris to a root tip and the root canal is avoided; and furthermore, the downward suction force in the root canal is reduced, so that the risk of breakage of the root canal file or the separation of instruments is effectively reduced.