Magnetic Dental Prosthesis Coupling Mechanism

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Solution Overview

Problem

Current dental prostheses, particularly all-on-four type prostheses, face challenges such as difficulty in home hygiene leading to peri-implantitis, frequent mechanical failures of titanium micro-screws, and the need for regular clinical maintenance due to complex disassembly requirements.

Innovation Solution

A dental device with a simplified structure that allows easy assembly and disassembly of dental prostheses from implant posts or intraosseous cavities, using a slider and movable element mechanism that can be magnetically controlled for secure and efficient coupling and uncoupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical screw joints are used to fix the prosthesis to the implant, then the prosthesis can be securely attached, but the screws often break due to mechanical stress and require complex disassembly procedures

Engineering Contradiction:
Improveprosthesis attachment reliabilityVSAvoidease of disassembly
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces the traditional mechanical screw joint system with a magnetic coupling system. The implant contains a permanent magnet that magnetically couples with a ferromagnetic element in the prosthesis base, eliminating the need for mechanical screws. This substitution maintains secure attachment while enabling easy disassembly by simply removing a retaining ring, allowing the prosthesis to be detached without specialized tools or procedures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic coupling system enables the user to perform maintenance and disassembly themselves without requiring a dentist or specialized equipment. The retaining ring can be easily removed by the user to detach the prosthesis for cleaning or maintenance, and reattached to secure it back onto the implant. This self-service capability eliminates the need for complex clinical procedures.

Inventive Principle:
Principle #25Self-service

2Stability of the object's composition

If the prosthesis is fixed securely to prevent detachment, then stability is improved, but the user cannot easily remove it for home hygiene maintenance

Engineering Contradiction:
Improveprosthesis stabilityVSAvoidease of removal for maintenance
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The magnetic coupling provides secure attachment through magnetic attraction force while allowing easy removal through simple mechanical intervention (removing the retaining ring). The magnetic force maintains stability during normal use including chewing and speaking, but the coupling can be easily broken by removing the retaining ring, enabling the user to detach the prosthesis for home hygiene maintenance without visiting the clinic.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If complex coupling mechanisms are used to enable easy removal, then ease of operation is improved, but the device complexity increases

Engineering Contradiction:
Improveease of prosthesis removalVSAvoidcoupling mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The coupling system is segmented into distinct functional components: the permanent magnet embedded in the implant, the ferromagnetic element in the prosthesis base, and the retaining ring for control. This segmentation allows each component to perform its specific function simply, avoiding the need for complex integrated mechanisms. The retaining ring acts as a simple mechanical latch that controls the magnetic coupling without adding complexity to the magnetic system itself.

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If magnetic coupling is used to allow easy detachment, then ease of operation is improved, but the magnetic force must be very high to withstand chewing loads

Engineering Contradiction:
Improveease of coupling and uncouplingVSAvoidmagnetic coupling force
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The retaining ring serves as a simple mechanical control element that the user can easily manipulate to engage or disengage the magnetic coupling. When the retaining ring is in place, it constrains the ferromagnetic element to maintain strong magnetic coupling that can withstand chewing loads. When removed, the magnetic coupling is released and the prosthesis can be easily detached. This simple mechanical control avoids the need for complex high-force magnetic control mechanisms.

Inventive Principle:
Principle #25Self-service

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 device enables users to remove and maintain their prostheses autonomously, reducing the risk of peri-implantitis and mechanical failures, while maintaining the stability and functionality of fixed prostheses, and extending the lifespan of removable prostheses by minimizing wear on components.

Implementation Method 1

The implant includes a permanent magnet and the base of the prosthesis includes, at least in part, a ferromagnetic element. The cursor is magnetized so that, when approached to external magnets, it can be subjected to a magnetic force that is opposite and greater than the elastic force of the spring.

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Implementation Method 2

The prosthesis therefore includes cavities suitable for housing at least part of the cursors. Basically, therefore, the coupling is achieved by the repulsion force produced by the springs that push the cursors into the cavities made in the prosthesis.

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP4171436B1Dental device
Publication Date: 2025.01.29 DI EDOARDO EMANUELE
  • EP4171436B1 patent drawingFigure 1a~1b
  • EP4171436B1 patent drawingFigure 2a~3
  • EP4171436B1 patent drawingFigure 4a~4b

AI summary

It is provided a dental device (1) comprising at least one base (2) defining a main axis (2a) and including at least a first portion (20) and a second portion (21), one of which is configured to be directly or indirectly constrained on of a osseous portion of a user and the other being configured to be constrained to one or more artificial teeth (3), constraint means (4) defining at least one constraint configuration wherein the first portion (20) and the second portion (21) are mutually constrained and a rest configuration in which the first portion (20) and the second portion (21) are separable at least along the main axis (2a), wherein the constraint means (4) comprise at least one wedge slider (40) movable along the main axis (2a) in such a way as to determine on the basis of the positioning the rest configuration and the constraint configuration, a movable element (41) at least partially counter-shaped to the slider (40 ) and expandible radially with respect to the main axis (2a) when pushed by the slider (40) in the constraint configuration, and an obstacle (42) configured to interfere with the movable element (41) when the constraint means (4) are in configuration constraint in such a way as to block the mutual translation of the portions (20, 21) along the main axis (2a), and wherein the cursor (40) and the movable element (41) are arranged on the first portion (20) and the obstacle (42) is arranged on the second portion (21).