Dental Ceramic Feeder Channel Layout for Bubble-Free Pressing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for producing dental restorations are inefficient and uneconomical, particularly when using lithium disilicate ceramics, as they struggle with producing complex shapes and achieving high-quality surface finishes, with existing technologies often resulting in errors and limited production capacity.

Innovation Solution

A CAD software module generates virtual models within a muffle, optimizing feeder channel design to align with isotherms, allowing for multiple dental restorations to be produced simultaneously with minimized temperature gradients and bubble formation, using a tree-like structure with feeder channels extending from a press channel, and adjusting flow resistance for efficient ceramic material filling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional lost-wax casting method is used for producing dental restorations, then the process is well-established and can handle various materials, but the production efficiency is low and it is uneconomical particularly for lithium disilicate ceramics

Engineering Contradiction:
Improveproduction efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent changes the fundamental manufacturing approach from lost-wax casting to direct digital printing and pressing of lithium disilicate ceramics. This parameter change enables higher production efficiency by eliminating multiple intermediate steps (wax model creation, mold making, casting, sintering) while maintaining manufacturing capability through computer-aided design and automated pressing systems

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical lost-wax casting process with a digital design and automated pressing system. Computer-aided design software generates the restoration geometry, and an automated pressing apparatus forms the ceramic restoration directly from powder material, eliminating the need for wax models, molds, and complex casting operations

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

2Productivity

If multiple dental restorations are produced simultaneously in a single press cycle, then production efficiency increases, but temperature gradients cause defects and reduced quality

Engineering Contradiction:
Improveproduction efficiencyVSAvoidsurface quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by positioning restorations in specific locations within the pressure chamber where temperature and pressure conditions are optimal. The system considers the thermal and mechanical environment at different chamber locations, placing restorations to minimize temperature gradients and ensure uniform heating and pressing, thereby maintaining high surface quality even when multiple restorations are produced simultaneously

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates equipotential conditions by designing the pressing process to ensure uniform temperature and pressure distribution across all restorations in the chamber. The system controls heating and pressing parameters to eliminate significant gradients, ensuring that all restorations experience similar processing conditions regardless of their position, thus preventing defects and maintaining consistent quality

Inventive Principle:
Principle #12Equipotentiality

3Ease of manufacture

If conventional feeder channel design is used, then the structure is simple, but bubble formation occurs and filling efficiency is reduced

Engineering Contradiction:
Improvestructural simplicityVSAvoidbubble formation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies curvature principles to the feeder channel design, using smooth curved transitions instead of sharp angles or straight connections. The feeder channels are designed with optimized curvature radii that facilitate smooth material flow from the pressure chamber into the restoration cavities, preventing turbulence and air entrapment that would cause bubble formation, while maintaining relatively simple overall structure

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

This approach enables the cost-effective and high-quality production of dental restorations with reduced errors and improved surface quality, allowing for simultaneous production of large and small restorations, minimizing bubble formation, and optimizing the pressing process for lithium disilicate ceramics.

Implementation Method 1

A press furnace has a press ram that penetrates the press channel and, according to a predetermined press program, further heats the blank together with the muffle, for example to approximately 1,100°C for a silicate or feldsplit ceramic, or to 1,600°C for an oxide ceramic

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

Following a precisely defined pressing program, pressure and heating are controlled in harmony with each other, so that the blank penetrates the cavity or cavities via the feeder channels during melting and the dental restoration is created there

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP2952154B1Method for producing dental restorations and dental ceramic production device
Publication Date: 2021.05.05 IVOCLAR VIVADENT AG
  • EP2952154B1 patent drawingFigure 1
  • EP2952154B1 patent drawingFigure 2
  • EP2952154B1 patent drawingFigure 3~4

AI summary

A method for manufacturing a dental restoration, - in which a dental restoration (12) is designed using CAD software and, in a forming step, is produced as a positive model (10), - which positive model (10) is impressioned using a mold and removed, and which mold is provided with a press channel (20) which is connected via a feeder channel (16), wherein the blank inserted into the press channel (20) is removed, - wherein at least one feeder channel (16) is automatically generated for each positive model (10) by a module of the CAD software, - wherein the module defines a virtual interior space within the mold for the arrangement of the dental restoration (12) in it, - wherein the feeder channel (16) extends obliquely away from the press channel (20), - wherein the positive model (10) extends in extension of the axis (14, 24) of the feeder channel (16) and the length of the virtual axis (14, 24) is maximized by the positive model (10).