Dental Handpiece Drive Control for Cutting Tool Fracture Prevention
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Solution Overview
Problem
Root canals of varying shapes and conditions pose a risk of fracture to cutting tools due to differences in curvature and calcification, leading to fractures during treatment, especially when smaller diameter tools are used.
Innovation Solution
A dental treatment apparatus controls the drive sequence to limit the cumulative angle of rotation of the cutting tool, ensuring it does not exceed a set value based on the tool's fracture angle, thereby preventing torsional fracture by alternating between forward and reverse rotation drives within specific patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the cutting tool is driven continuously in one direction to efficiently cut and enlarge the root canal, then the productivity is improved, but the cutting tool may be fractured by excessive cumulative rotation angle
Solution Approach 1:
The patent applies periodic action by alternating the cutting tool between forward rotation and reverse rotation in a controlled cycle. The drive control unit performs forward rotation drive for a first time period, then reverse rotation drive for a second time period, creating a periodic motion pattern. This periodic alternation prevents cumulative rotation angle from exceeding the fracture angle while maintaining continuous cutting action, thus resolving the contradiction between productivity and reliability.
2Adaptability or versatility
If smaller diameter cutting tools are used to treat narrow root canals, then the adaptability to different root canal sizes is improved, but the cutting tool becomes more susceptible to fracture
Solution Approach 1:
The patent applies dynamics by making the drive parameters dynamic rather than static. The drive control unit adjusts rotation direction and time periods based on real-time cumulative rotation angle feedback. For smaller diameter tools with lower fracture angles, the system dynamically reduces the first time period or increases the second time period to keep cumulative rotation below the tool-specific fracture threshold, thereby maintaining both adaptability to different root canal sizes and fracture resistance.
3Reliability
If the cumulative rotation angle is strictly limited to prevent fracture, then the cutting tool reliability is improved, but the cutting efficiency may be reduced
Solution Approach 1:
The patent applies continuity of useful action by ensuring that the cutting tool remains in continuous motion alternating between forward and reverse rotation, with no idle time. The drive control unit carefully selects the second time period to be just sufficient to prevent fracture while minimizing the interruption to cutting action. This maintains continuous useful cutting action while preventing fracture, resolving the contradiction between reliability and productivity.
Data Source
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AI summary
The present invention provides a dental treatment apparatus driving a cutting tool attached to a head, the dental treatment apparatus controlling drive allowing prevention of fracture of a cutting tool, and a method of driving the same. The dental treatment apparatus according to the present invention includes a handpiece (1) holding a cutting tool (5) in its head (2), a drive portion driving the cutting tool (5) held by the head (2), and a control portion (11) controlling the drive portion in accordance with a drive sequence. The drive sequence includes at least one forward rotation drive for rotating the cutting tool (5) in a cutting direction to cut a treatment portion and at least one reverse rotation drive for rotating the cutting tool (5) in a non-cutting direction. Under the control of the drive portion in accordance with the drive sequence, a cumulative amount of rotation which is an accumulation of an amount of rotation in forward rotation drive and an amount of rotation in reverse rotation drive does not exceed a set value at any time point.