Dental Blank Retaining Ring for Vibration-Damped Edge Milling

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Solution Overview

Problem

Existing dental disc holder systems face challenges in maximizing material utilization while maintaining stability during milling, as the need for a wide edge to prevent breakage limits the proximity to the edge that can be milled, and existing solutions do not effectively absorb vibrations that can cause breakage in brittle ceramic materials.

Innovation Solution

A dental disc holder ring with a C-shaped or L-shaped cross-section, composed of a harder and softer material combination, where the softer component surrounds the disc and applies pretension to absorb vibrations and stabilize the disc during milling, allowing for a smaller remaining edge and improved material utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a wide non-millable edge is maintained to ensure stability during milling, then the stability of the dental blank is improved, but the material utilization is reduced

Engineering Contradiction:
Improvestability of dental blankVSAvoidmaterial utilization
Core Design Contradiction:
Stability of the object's compositionVSLoss of substance

Solution Approach 1:

The retaining rim is divided into multiple discrete retaining elements distributed around the periphery of the dental blank, rather than forming a continuous rigid ring. This segmentation allows the blank to be stabilized at multiple points while reducing overall material removal and enabling better material utilization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retaining elements are strategically positioned at specific locations around the blank periphery where they provide maximum stabilization benefit. This localized approach ensures stability is provided exactly where needed during milling operations, rather than requiring a uniform wide edge throughout.

Inventive Principle:
Principle #3Local quality

2Loss of substance

If milling is performed close to the edge to maximize material utilization, then the material utilization is improved, but the stability of the remaining edge is compromised

Engineering Contradiction:
Improvematerial utilizationVSAvoidstability of remaining edge
Core Design Contradiction:
Loss of substanceVSStability of the object's composition

Solution Approach 1:

The retaining elements are pre-positioned on the dental blank before the milling operation begins. These elements create stabilization zones that protect the remaining edges during milling, allowing the milling process to proceed closer to the edge without compromising the integrity of the remaining material.

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If a single-piece retaining rim is used to stabilize the dental blank, then the stability is improved, but the complexity of the device increases

Engineering Contradiction:
Improvestability of dental blankVSAvoidcomplexity of retaining rim
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The retaining rim is segmented into multiple discrete retaining elements that can be individually positioned and secured on the dental blank. This segmentation simplifies the overall device structure compared to a single-piece rigid ring, while still providing effective stabilization through distributed support points.

Inventive Principle:
Principle #1Segmentation

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 solution reduces the tendency of the dental blank to break during milling by damping vibrations and allowing for closer milling to the edge, thereby optimizing material use and reducing waste, while also providing a secure and precise positioning mechanism.

Implementation Method 1

The vibrations and stresses introduced by the milling machine into the comparatively brittle ceramic material of the dental blank are gently absorbed by the softer support material. This surprisingly makes milling possible even with a smaller remaining free edge

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 2

the inventive solution attempts to equalize and smooth out the induced stress peaks, so that, viewed over the time integral, there is no greater or lesser stress loading. Rather, it is influenced in such a way that the vibrations are dampened at their stress peaks

Methodology Applied
Scientific EffectStress equalization: Viscoelasticity

Implementation Method 3

The retaining ring according to the invention also holds the dental blank under pre-tension, i.e. under pressure

Methodology Applied
Scientific EffectPre-tension: Tension

Data Source

PatentEP3995106B1Dental blank retaining ring
Publication Date: 2024.10.02 IVOCLAR VIVADENT AG
  • EP3995106B1 patent drawingFigure 1~2
  • EP3995106B1 patent drawingFigure 3~4
  • EP3995106B1 patent drawingFigure 5~6

AI summary

The invention relates to a dental disc retaining ring, in particular with a retaining projection (22) forming an undercut, wherein the retaining ring (10) consists of at least two components (26, 28) whose harder component overlaps the softer one.