Variable Geometry Endodontic Instrument for Root Canal Shaping
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Solution Overview
Problem
Current endodontic instruments for reaming root canals face issues such as increased torque and risk of breakage due to friction, inability to maintain sharpness for effective shaping, and lack of adaptability for variable treatment sequences along the canal length, leading to potential deformation of canal walls and inefficiencies in curved areas.
Innovation Solution
The development of an endodontic instrument with variable cutting, scraping, and neutral zones along its length, featuring helical flutes with adjustable cutting edge angles to ensure sharpness where needed, dullness where necessary, and flexibility in curved areas, allowing for progressive changes in cutting and scraping functions from the tip to the holding piece.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the cutting edges are made sharp to effectively shape the root canal, then the shaping capability is improved, but the risk of breaking the instrument and deforming canal walls increases
Solution Approach 1:
The patent applies local quality by creating different zones along the working part with distinct cutting edge properties. The tip portion has sharper edges for effective cutting and shaping, while the upper portions have progressively blunter edges. This gradient distribution allows the instrument to perform cutting functions where needed while maintaining flexibility and reducing breakage risk in other areas.
2Strength
If the instrument is made rigid to maintain structural strength, then the strength is improved, but the flexibility in curved areas decreases
Solution Approach 1:
The instrument implements local quality through variable cross-sectional geometry along its length. The tip portion has a smaller cross-section for flexibility and navigation through curved canals, while the upper portions have progressively larger cross-sections for structural strength and torque transmission. This gradient design allows the instrument to bend and adapt to curved canal geometries while maintaining sufficient rigidity for effective cutting.
3Ease of manufacture
If the helical flutes are designed with uniform geometry, then the manufacturing is simplified, but the adaptability for variable treatment sequences along the canal length is reduced
Solution Approach 1:
The patent applies dynamics by transitioning from a static, uniform flute geometry to a dynamic, variable geometry along the working part. The flute parameters (such as helix angle, depth, and cross-sectional shape) change progressively from the tip to the upper portions, allowing the instrument to adapt its cutting and scraping characteristics to different depths and treatment requirements within the root canal.
4Object-affected harmful factors
If the cutting edges are blunted to prevent material nicking, then the risk of deforming canal walls is reduced, but the heating and friction increase
Solution Approach 1:
The instrument applies local quality by creating a gradient in cutting edge sharpness along its length. The tip portion maintains sharper edges for effective cutting with controlled friction, while the upper portions have blunter edges that scrape and smooth the canal walls without causing nicking or deformation. This zoned approach allows the instrument to perform both cutting and smoothing functions simultaneously at different locations.
Data Source
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AI summary
The invention relates to an endodontic instrument (10) for drilling root canals, in particular a flexible drilling instrument, comprising a working part (11) and a securing end fitting (12) intended for mounting the instrument in a mandrel of a contra-angle-type support provided with an electric motor used to drive same clockwise. The casing of the working part (11) is conical along the length thereof and ends in a tip (13). The working part (11) is provided with a spiral flute (14) forming a ridge (20) having a cutting edge (24). The drill bit, relief and cutting angles defined by the cutting edge (24) can be varied along the length of the working part (11) so that the instrument is particularly sharp in the area near the tip (13) and so that the profile of the cutting ridge (24) becomes progressively more blunt along the length of the instrument (10).